We have studied the optical spectra of low-dimensional semiconductor systems by calculating all possible optical transitions between electronic states. Optical absorption and emission have been obtained under differen...We have studied the optical spectra of low-dimensional semiconductor systems by calculating all possible optical transitions between electronic states. Optical absorption and emission have been obtained under different carrier population conditions and in different photon wavelengths. The line-shapes of the peaks in the optical spectrum are determined by the density of electronic states of the system, and the symmetries and intensities of these peaks can be improved by reducing the dimensionality of the system. Optical gain requires in general a population inversion, whereas for a quantum-dot system, there exists a threshold value of the population inversion.展开更多
Carbon-based low-dimensional materials(CLDM)with elemental carbon as the main component have unique physical and chemical properties,and become the focus of research in many fields including energy,environmental prote...Carbon-based low-dimensional materials(CLDM)with elemental carbon as the main component have unique physical and chemical properties,and become the focus of research in many fields including energy,environmental protection,and information technology.Notably,cellulose acetate,the main component of cigarette butts(CBs),is a one-dimensional precursor with a large specific surface area and aspect ratio.Still,their usefulness as building fillers has often been underestimated before.This review summarizes recent advances in CBs recycling and provides suggested guidelines for its use as a CLDM material in renewable energy.Specifically,we first describe the harmful effects of CBs as pollutants in our lives to emphasize the importance of proper recycling.We then summarize previous methods of recycling CBs waste,including clay bricks,asphalt concrete pavement,gypsum,acoustic materials,chemisorption,vector control,and corrosion control.The potential applications of CBs include triboelectric nanogenerator applications,flexible batteries,enhanced metal-organic framework material energy storage devices,and carbon-based hydrogen storage.Finally,the advantages of utilizing CBs-derived CLDM materials over conventional solutions in the energy field are discussed.This review will provide new avenues for solving the intractable problem of CBs and reducing the manufacturing costs of renewable materials.展开更多
Linearly polarized photodetectors(PDs),leveraging the inherent structural and material information encoded in light's polarization state,hold transformative potential for applications ranging from remote sensing t...Linearly polarized photodetectors(PDs),leveraging the inherent structural and material information encoded in light's polarization state,hold transformative potential for applications ranging from remote sensing to biomedical imaging.Traditional systems that rely on external polarizing elements face challenges in miniaturization and efficiency,driving interest in materials with intrinsic anisotropy.Low-dimensional metal halide perovskites,distinguished by their tunable bandgaps,high carrier mobility,and quantum confinement effects,have emerged as a groundbreaking platform for next-generation polarized PDs.This review comprehensively summarizes the theory,materials,and device engineering of linearly polarized PDs based on low-dimensional perovskites.It aims to elucidate polarization mechanisms across dimensions by establishing a rigorous theoretical foundation for linearly polarized PDs of low-dimensional perovskites.Beyond theoretical insights,the review also highlights cutting-edge fabrication techniques for one-dimensional nano wires and two-dimensional heterostructures,along with performance benchmarks of state-of-the-art devices.By integrating experimental advancements with theoretical insights,this work not only advances the fundamental understanding of polarization mechanisms but also outlines actionable pathways for optimizing device performance,stability,and scalability,which may serve as a critical resource for researchers aiming to harness the full potential of low-dimensional perovskites in polarized optoelectronics.展开更多
The growing complexity of electromagnetic(EM)interference has driven significant demand for next-generation absorbers that combine lightweight,flexibility,and good electromagnetic attenuation capability.The low-dimens...The growing complexity of electromagnetic(EM)interference has driven significant demand for next-generation absorbers that combine lightweight,flexibility,and good electromagnetic attenuation capability.The low-dimensional ternary Co_(3)ZnC/Co/CNT composites with hollow structures have been synthesized through in-situ polymerization and high-temperature carbonization.The unique integration of low-dimensional nanostructures and multicomponent heterointerfaces confers exceptional EM absorption properties,achieving a reflection loss of−70.0 dB and significantly reducing radar cross section(RCS)scattering signals.It is particularly meaningful that the numerical simulation of Co_(3)ZnC/Co/CNT metama-terial reveals ultrawideband absorption performance,achieving 10.7 GHz(7.3-18.0 GHz)at a thickness of 4.5 mm and extending to 15 GHz(3.0-18.0 GHz)with a 10.5 mm.Moreover,the Co_(3)ZnC/Co/CNT composites retain meritorious EM absorption properties after flexible film formation,broadening their usability and application scope.These investigations will provide seminal insights encompassing theoretical validation,experimental synthesis,and practical application for the next generation of absorbers.展开更多
Bacterial infections have always been a major threat to human health.Skin wounds are frequently exposed to the external environment,and they may become contaminated by bacteria derived from the surrounding skin,the lo...Bacterial infections have always been a major threat to human health.Skin wounds are frequently exposed to the external environment,and they may become contaminated by bacteria derived from the surrounding skin,the local environment,and the patient’s own endogenous sources.Contaminated wounds may enter a state of chronic inflammation that impedes healing.Urgent development of antibacterial wound dressings capable of effectively combating bacteria and overcoming resistance is necessary.Nanotechnology and nanomaterials present promising potential as innovative strategies for antimicrobial wound dressings,owing to their robust antibacterial characteristics and the inherent advantage of avoiding antibiotic resistance.Therefore,this review provides a concise overview of the antimicrobial mechanisms exhibited by low-dimensional nanomaterials.It further categorizes common low-dimensional antimicrobial nanomaterials into zero-dimensional(0D),one-dimensional(1D)and two-dimensional(2D)nanomaterials based on their structural characteristics,and gives a detailed compendium of the latest research advances and applications of different low-dimensional antimicrobial nanomaterials in wound healing,which could be helpful for the development of more effective wound dressings.展开更多
Low-dimensional(including two-dimensional[2D],one-dimensional[1D],and zero-dimensional[0D])semiconductor materials have great potential in electronic/optoelectronic applications due to their unique structure and chara...Low-dimensional(including two-dimensional[2D],one-dimensional[1D],and zero-dimensional[0D])semiconductor materials have great potential in electronic/optoelectronic applications due to their unique structure and characteristics.Many 2D(such as transition metal dichalcogenides and black phosphorus)and 1D(such as NWs)materials have demonstrated superior performance in field effect transistors,photodetectors(PDs),and some flexible devices.And in some hybrid structures of 0D materials and 1D or 2D materials,the modification of 1D and 2D devices by 0D materials is embodied.This type of hybrid heterostructure has a larger performance optimization compared with the original.In the application of PDs,the variety of lowdimensional materials and properties enable wide-spectrum detection from ultraviolet UV to infrared,which provide a potential option for PDs under various conditions.For flexible electronic devices,high performance and mechanical stability are two important features.Low-dimensional materials offer unparalleled advantages in flexible devices.In this review,we will focus on the various low-dimensional materials that have been extensively studied and their applications in the electronics/optoelectronic and flexible electronics.From the composition and lattice structure of materials(including alloys)to the construction of various devices and heterostructures,we will introduce their application and recent development under various conditions.These works can provide valuable guidance for the construction and application of more highperformance and multifunctional devices.展开更多
In recent years,low-dimensional transition metal chalcogenide(TMC)materials have garnered growing research attention due to their superior electronic,optical,and catalytic properties compared to their bulk counterpart...In recent years,low-dimensional transition metal chalcogenide(TMC)materials have garnered growing research attention due to their superior electronic,optical,and catalytic properties compared to their bulk counterparts.The controllable synthesis and manipulation of these materials are crucial for tailoring their properties and unlocking their full potential in various applications.In this context,the atomic substitution method has emerged as a favorable approach.It involves the replacement of specific atoms within TMC structures with other elements and possesses the capability to regulate the compositions finely,crystal structures,and inherent properties of the resulting materials.In this review,we present a comprehensive overview on various strategies of atomic substitution employed in the synthesis of zero-dimensional,one-dimensional and two-dimensional TMC materials.The effects of substituting elements,substitution ratios,and substitution positions on the structures and morphologies of resulting material are discussed.The enhanced electrocatalytic performance and photovoltaic properties of the obtained materials are also provided,emphasizing the role of atomic substitution in achieving these advancements.Finally,challenges and future prospects in the field of atomic substitution for fabricating low-dimensional TMC materials are summarized.展开更多
Polarized-sensitive image sensors are a kind of photodetector with great development potential due to their enhanced ability to detect and identify the target objects from the aspect of spatial,spectral and polarized ...Polarized-sensitive image sensors are a kind of photodetector with great development potential due to their enhanced ability to detect and identify the target objects from the aspect of spatial,spectral and polarized information.Recently,low-dimensional anisotropic materials with inherent anisotropic properties,ultrathin thickness,tunable bandgap and feasible integration with complementary metal oxide semiconductor(CMOS)fabrication processes have attracted great interest for their facilitation of polarized photodetector devices miniaturization.Maximizing the polarized detection performance of low-dimensional materials to satisfy realistic needs stimulates the exploration of modulation of anisotropic properties.In this review,we comprehensively introduce the latest research progress in modulating the optical and optoelectronic anisotropy characteristics of low-dimensional materials.The strategy of anisotropy regulation through crystal structure engineering and coupling system is discussed emphatically.Then,the latest progress in image recognition applications using anisotropic low-dimensional materials is reviewed in detail.Finally,we summarize the challenge and propose future opportunities in the practical application of polarized-sensitive imaging photodetectors based on low-dimensional anisotropic materials.展开更多
The use of low-dimensional(LD)perovskite materials is crucial for achieving high-performance perovskite solar cells(PSCs).However,LD perovskite films fabricated by conventional approaches give rise to full coverage of...The use of low-dimensional(LD)perovskite materials is crucial for achieving high-performance perovskite solar cells(PSCs).However,LD perovskite films fabricated by conventional approaches give rise to full coverage of the underlying 3D perovskite films,which inevitably hinders the transport of charge carriers at the interface of PSCs.Here,we designed and fabricated LD perovskite structure that forms net-like morphology on top of the underlying three-dimensional(3D)perovskite bulk film.The net-like LD perovskite not only reduced the surface defects of 3D perovskite film,but also provided channels for the vertical transport of charge carriers,effectively enhancing the interfacial charge transfer at the LD/3D hetero-interface.The net-like morphological design comprising LD perovskite effectively resolves the contradiction between interfacial defect passivation and carrier extraction across the hetero-interfaces.Furthermore,the net-like LD perovskite morphology can enhance the stability of the underlying 3D perovskite film,which is attributed to the hydrophobic nature of LD perovskite.As a result,the net-like LD perovskite film morphology assists PSCs in achieving an excellent power conversion efficiency of up to 24.6%with over 1000 h long-term operational stability.展开更多
Metal oxide semiconductors(MOSs) are attractive candidates as functional parts and connections in nanodevices.Upon spatial dimensionality reduction, the ubiquitous strain encountered in physical reality may result in ...Metal oxide semiconductors(MOSs) are attractive candidates as functional parts and connections in nanodevices.Upon spatial dimensionality reduction, the ubiquitous strain encountered in physical reality may result in structural instability and thus degrade the performance of MOS. Hence, the basic insight into the structural evolutions of low-dimensional MOS is a prerequisite for extensive applications, which unfortunately remains largely unexplored. Herein, we review the recent progress regarding the mechanical deformation mechanisms in MOSs, such as CuO and ZnO nanowires(NWs). We report the phase transformation of CuO NWs resulting from oxygen vacancy migration under compressive stress and the tensile strain-induced phase transition in ZnO NWs. Moreover, the influence of electron beam irradiation on interpreting the mechanical behaviors is discussed.展开更多
Semiconductor optoelectronics devices,capable of converting electrical power into light or conversely light into electrical power in a compact and highly efficient manner represent one of the most advanced technologie...Semiconductor optoelectronics devices,capable of converting electrical power into light or conversely light into electrical power in a compact and highly efficient manner represent one of the most advanced technologies ever developed,which has profoundly reshaped the modern life with a wide range of applications.In recent decades,semiconductor technology has rapidly evolved from first-generation narrow bandgap materials(Si,Ge)to the latest fourth-generation ultra-wide bandgap semiconductor(GaO,diamond,AlN)with enhanced performance to meet growing demands.Additionally,merging semiconductor devices with other techniques,such as computer assisted design,state-of-the-art micro/nano fabrications,novel epitaxial growth,have significantly accelerated the development of semiconductor optoelectronics devices.Among them,integrating metasurfaces with semiconductor optoelectronic devices have opened new frontiers for on-chip control of their electromagnetic response,providing access to previously inaccessible degrees of freedom.We review the recent advances in on-chip control of a variety of semiconductor optoelectronic devices using integrated metasurfaces,including semiconductor lasers,semiconductor light emitting devices,semiconductor photodetectors,and low dimensional semiconductors.The integration of metasurfaces with semiconductors offers wafer-level ultracompact solutions for manipulating the functionalities of semiconductor devices,while also providing a practical platform for implementing cuttingedge metasurface technology in real-world applications.展开更多
Although there are numerous optical spectroscopy techniques and methods that have been used to extract the fundamental bandgap of a semiconductor,most of them belong to one of these three approaches:(1)the excitonic a...Although there are numerous optical spectroscopy techniques and methods that have been used to extract the fundamental bandgap of a semiconductor,most of them belong to one of these three approaches:(1)the excitonic absorption,(2)modulation spectroscopy,and(3)the most widely used Tauc-plot.The excitonic absorption is based on a many-particle theory,which is physically the most correct approach,but requires more stringent crystalline quality and appropriate sample preparation and experimental implementation.The Tauc-plot is based on a single-particle theo⁃ry that neglects the many-electron effects.Modulation spectroscopy analyzes the spectroscopy features in the derivative spectrum,typically,of the reflectance and transmission under an external perturbation.Empirically,the bandgap ener⁃gy derived from the three approaches follow the order of E_(ex)>E_(MS)>E_(TP),where three transition energies are from exci⁃tonic absorption,modulation spectroscopy,and Tauc-plot,respectively.In principle,defining E_(g) as the single-elec⁃tron bandgap,we expect E_(g)>E_(ex),thus,E_(g)>E_(TP).In the literature,E_(TP) is often interpreted as E_(g),which is conceptual⁃ly problematic.However,in many cases,because the excitonic peaks are not readily identifiable,the inconsistency be⁃tween E_(g) and E_(TP) becomes invisible.In this brief review,real world examples are used(1)to illustrate how excitonic absorption features depend sensitively on the sample and measurement conditions;(2)to demonstrate the differences between E_(ex),E_(MS),and E_(TP) when they can be extracted simultaneously for one sample;and(3)to show how the popular⁃ly adopted Tauc-plot could lead to misleading results.Finally,it is pointed out that if the excitonic absorption is not ob⁃servable,the modulation spectroscopy can often yield a more useful and reasonable bandgap than Tauc-plot.展开更多
Radiation doses to patients in diagnostics and interventional radiology need to be optimized to comply with the principles of radiation protection in medical practice. This involves using specific detectors with respe...Radiation doses to patients in diagnostics and interventional radiology need to be optimized to comply with the principles of radiation protection in medical practice. This involves using specific detectors with respective diagnostic beams to carry out quality control/quality assurance tests needed to optimize patient doses in the hospital. Semiconductor detectors are used in dosimetry to verify the equipment performance and dose to patients. This work aims to assess the performance, energy dependence, and response of five commercially available semiconductor detectors in RQR, RQR-M, RQA, and RQT at Secondary Standard Dosimetry for clinical applications. The diagnostic beams were generated using Exradin A4 reference ion chamber and PTW electrometer. The ambient temperature and pressure were noted for KTP correction. The detectors designed for RQR showed good performance in RQT beams and vice versa. The detectors designed for RQR-M displayed high energy dependency in other diagnostic beams. The type of diagnostic beam quality determines the response of semiconductor detectors. Therefore, a detector should be calibrated according to the beam qualities to be measured.展开更多
Semiconductors and related fields today hold vast application prospects.The semiconductor wafer fabrication process involves steps such as substrate preparation and epitaxy,which occur in high-temperature corrosive en...Semiconductors and related fields today hold vast application prospects.The semiconductor wafer fabrication process involves steps such as substrate preparation and epitaxy,which occur in high-temperature corrosive environments.Consequently,components like crucibles,susceptors and wafer carriers require carbon-based materials such as graphite and carbon-carbon composites.However,traditional carbon materials underperform in these extreme conditions,failing to effectively address the challenges.This leads to issues including product contamination and shortened equipment lifespan.Therefore,effective protection of carbon materials is crucial.This paper reviews current research status on the preparation methods and properties of corrosion-resistant coatings within relevant domestic and international fields.Preparation methods include various techniques such as physical vapor deposition(PVD),chemical vapor deposition(CVD)and the sol-gel method.Furthermore,it offers perspectives on future research directions for corrosion-resistant coated components in semiconductor equipment.These include exploring novel coating materials,improving coating preparation processes,enhancing coating corrosion resistance,as well as further investigating the interfacial interactions between coatings and carbon substrates to achieve better adhesion and compatibility.展开更多
Organic semiconductor materials have shown unique advantages in the development of optoelectronic devices due to their ease of preparation,low cost,lightweight,and flexibility.In this work,we explored the application ...Organic semiconductor materials have shown unique advantages in the development of optoelectronic devices due to their ease of preparation,low cost,lightweight,and flexibility.In this work,we explored the application of the organic semiconductor Y6-1O single crystal in photodetection devices.Firstly,Y6-1O single crystal material was prepared on a silicon substrate using solution droplet casting method.The optical properties of Y6-1O material were characterized by polarized optical microscopy,fluorescence spectroscopy,etc.,confirming its highly single crystalline performance and emission properties in the near-infrared region.Phototransistors based on Y6-1O materials with different thicknesses were then fabricated and tested.It was found that the devices exhibited good visible to near-infrared photoresponse,with the maximum photoresponse in the near-infrared region at 785 nm.The photocurrent on/off ratio reaches 10^(2),and photoresponsivity reaches 16 mA/W.It was also found that the spectral response of the device could be regulated by gate voltage as well as the material thickness,providing important conditions for optimizing the performance of near-infrared photodetectors.This study not only demonstrates the excellent performance of organic phototransistors based on Y6-1O single crystal material in near-infrared detection but also provides new ideas and directions for the future development of infrared detectors.展开更多
Realizing ferromagnetic semiconductors with high Curie temperature TC is still a challenge in spintronics.Recent experiments have reported two-dimensional(2D)room temperature ferromagnetic metals,such as monolayer Cr_...Realizing ferromagnetic semiconductors with high Curie temperature TC is still a challenge in spintronics.Recent experiments have reported two-dimensional(2D)room temperature ferromagnetic metals,such as monolayer Cr_(3)Te_(6).In this paper,through density functional theory(DFT)calculations,we propose a method to obtain 2D high TC ferromagnetic semiconductors through element replacement in these ferromagnetic metals.We predict that monolayer(Cr_(4/6),Mo_(2/6))_(3)Te_(6),created via element replacement in monolayer Cr_(3)Te_(6),is a room-temperature ferromagnetic semiconductor exhibiting a band gap of 0.34 eV and a TC of 384 K.Our analysis reveals that the metal-to-semiconductor transition stems from the synergistic interplay of Mo-induced lattice distortion,which resolves band overlap,and the electronic contributions of Mo dopants,which further drive the formation of a distinct band gap.The origin of the high TC is traced to strong superexchange coupling between magnetic ions,analyzed via the superexchange model with DFT and Wannier function calculations.Considering the fast developments in fabrication and manipulation of 2D materials,our theoretical results propose an approach to explore high-temperature ferromagnetic semiconductors derived from experimentally obtained 2D high-temperature ferromagnetic metals through element replacement.展开更多
All-inorganic CsPbBr_(3) perovskite quantum dots(QDs)have attracted extensive attention in photoelectric detection for their excellent photoelectric properties and stability.However,the CsPbBr_(3) quantum dot film exh...All-inorganic CsPbBr_(3) perovskite quantum dots(QDs)have attracted extensive attention in photoelectric detection for their excellent photoelectric properties and stability.However,the CsPbBr_(3) quantum dot film exhibits a high non-radiative recombination rate,and the mismatch in energy levels with the carbon electrode weakens hole extraction efficiency.These reduces the device's performance.To improve this,a semiconductor photodetector based on fluorine-doped tin oxide(FTO)/dense titanium dioxide(c-TiO_(2))/mesoporous titanium dioxide(m-TiO_(2))/CsPbBr_(3) QDs/CsPbBr_(x)I_(3-x)(x=2,1.5,1)QDs/C struc-ture was studied.By adjusting the Br-:I-ratio,the synthesized CsPbBr_(x)I_(3-x)(x=2,1.5,1)QDs showed an adjustable band gap width of 2.284-2.394 eV.And forming a typeⅡband structure with CsPbBr_(3) QDs,which reduced the valence band offset between the active layer and the carbon electrode,this promoted carrier extraction and reduced non-radiative recombination rate.Compared with the original device(the photosensitive layer is CsPbBr_(3) QDs),the performance of the photodetector based on the CsPbBr_(3) QDs/CsPbBr2I QDs heterostructure is significantly improved,the responsivity(R)increased by 73%,the specific detectivity rate(D^(*))increased from 6.98×10^(12) to 3.19×10^(13) Jones,the on/off ratio reached 106.This study provides a new idea for the development of semiconductor tandem detectors.展开更多
The effect of intermetallic particles on the corrosion of 6061 aluminum alloy and its coating used in semiconductor processing systems was systematically studied via liquid and gas experiments and micromorphology char...The effect of intermetallic particles on the corrosion of 6061 aluminum alloy and its coating used in semiconductor processing systems was systematically studied via liquid and gas experiments and micromorphology characterization.The results revealed that a huge difference of corrosion resistance between imported and domestic 6061 aluminum alloys in HCl solution and gas acid mist experiments mainly was attributed to the different size and amount of Al_(15)(Fe,Mn)_(3)Si_(2).The corrosion resistance of domestic 6061 alloy in dry/wet semiconductor electronic special gas environments was worse than that of imported aluminum alloy,and there are great differences in the corrosion mechanism of 6061 alloy caused by the second phase in the two dry/wet environments.And the corrosion resistance of the hard anodized alumina film was closely related to the microscopic morphology of holes.The vertical and elongatedα-Al_(15)(Mn,Fe)_(3)Si_(2) phase was formed in the rolled aluminum alloy that has been rolled perpendicular to the surface of the substrate.Compared to the horizontal long hole,the longitudinal long holes generated by the verticalα-Al_(15)(Mn,Fe)_(3)Si_(2) phase will enable the corrosive medium to reach the substrate rapidly,which significantly weakens the corrosion resistance of the hard anodized film.展开更多
We report the manipulation of ferromagnetism in magnetic semiconductor Ba(Zn,Mn,Cu)_(2)As_(2)through chemical pressure.The substitutions of Sr for Ba and Sb for As introduce positive and negative chemical pressures,re...We report the manipulation of ferromagnetism in magnetic semiconductor Ba(Zn,Mn,Cu)_(2)As_(2)through chemical pressure.The substitutions of Sr for Ba and Sb for As introduce positive and negative chemical pressures,respectively;neither Sr doping nor Sb doping change the tetragonal crystal structure.Based on Ba(Zn_(0.75)Mn_(0.125)Cu_(0.125))_(2)As_(2)with T_(C)~34 K,10%Sr/Ba substitutions significantly improve T_(C)by~15%to 39 K,whereas 10%Sb/As substitutions substantially reduce TCby~47%to 18 K.The AC magnetic susceptibility measurements indicate that Sr-doped and Sb-doped samples evolve into a spin glass state below the spin freezing temperature Tf.Electrical transport measurements demonstrate that Sr-doped specimens retain semiconducting behavior;additionally,they display a significant negative magnetoresistance effect under applied magnetic fields and the magnetoresistance reaches~-19%at 8 T.展开更多
TiO_(2)is a well-known photocatalyst with a band gap of 3.2 eV,yet its ability to absorb light is limited to the short wavelengths of ultraviolet light.To achieve a more effective photocatalytic material,we have desig...TiO_(2)is a well-known photocatalyst with a band gap of 3.2 eV,yet its ability to absorb light is limited to the short wavelengths of ultraviolet light.To achieve a more effective photocatalytic material,we have designed two-dimensional semiconductor TiOS materials using swarm intelligence algorithms combined with first-principles calculations.Three stable low-energy structures with space groups of P2_(1)/m,P3m1 and P2_(1)/c are identified.Among these structures,the Janus P3m1 phase is a direct bandgap semiconductor,while the P2_(1)/m and P2_(1)/c phases are indirect bandgap semiconductors.Utilizing the accurate hybrid density functional HSE06 method,the band gaps of the three structures are calculated to be 2.34 eV(P2_(1)/m),2.24 eV(P3m1)and 3.22 eV(P2_(1)/c).Optical calculations reveal that TiOS materials exhibit a good light-harvesting capability in both visible and ultraviolet spectral ranges.Moreover,the photocatalytic calculations also indicate that both P2_(1)/m and P3m1 TiOS can provide a strong driving force for converting H_(2)O to H_(2)and O_(2)in an acidic environment with pH=0.The structural stabilities,mechanical properties,electronic structures and hydrogen evolution reaction activities are also discussed in detail.Our research suggests that two-dimensional TiOS materials have potential applications in both semiconductor devices and photocatalysis.展开更多
文摘We have studied the optical spectra of low-dimensional semiconductor systems by calculating all possible optical transitions between electronic states. Optical absorption and emission have been obtained under different carrier population conditions and in different photon wavelengths. The line-shapes of the peaks in the optical spectrum are determined by the density of electronic states of the system, and the symmetries and intensities of these peaks can be improved by reducing the dimensionality of the system. Optical gain requires in general a population inversion, whereas for a quantum-dot system, there exists a threshold value of the population inversion.
基金supported by Hubei Province Technology Innovation Program Project(2024BCB073)the National Natural Science Foundation of China(52402249)the China Postdoctoral Science Foundation(2021M690930).
文摘Carbon-based low-dimensional materials(CLDM)with elemental carbon as the main component have unique physical and chemical properties,and become the focus of research in many fields including energy,environmental protection,and information technology.Notably,cellulose acetate,the main component of cigarette butts(CBs),is a one-dimensional precursor with a large specific surface area and aspect ratio.Still,their usefulness as building fillers has often been underestimated before.This review summarizes recent advances in CBs recycling and provides suggested guidelines for its use as a CLDM material in renewable energy.Specifically,we first describe the harmful effects of CBs as pollutants in our lives to emphasize the importance of proper recycling.We then summarize previous methods of recycling CBs waste,including clay bricks,asphalt concrete pavement,gypsum,acoustic materials,chemisorption,vector control,and corrosion control.The potential applications of CBs include triboelectric nanogenerator applications,flexible batteries,enhanced metal-organic framework material energy storage devices,and carbon-based hydrogen storage.Finally,the advantages of utilizing CBs-derived CLDM materials over conventional solutions in the energy field are discussed.This review will provide new avenues for solving the intractable problem of CBs and reducing the manufacturing costs of renewable materials.
基金financially supported by the National Natural Science Foundation of China(Nos.62205011,52473305,92256202,and 12261131500)the Fundamental Research Funds for the Central Universities(No.PY2507)Qian Xuesen Youth Innovation Fund of CASC
文摘Linearly polarized photodetectors(PDs),leveraging the inherent structural and material information encoded in light's polarization state,hold transformative potential for applications ranging from remote sensing to biomedical imaging.Traditional systems that rely on external polarizing elements face challenges in miniaturization and efficiency,driving interest in materials with intrinsic anisotropy.Low-dimensional metal halide perovskites,distinguished by their tunable bandgaps,high carrier mobility,and quantum confinement effects,have emerged as a groundbreaking platform for next-generation polarized PDs.This review comprehensively summarizes the theory,materials,and device engineering of linearly polarized PDs based on low-dimensional perovskites.It aims to elucidate polarization mechanisms across dimensions by establishing a rigorous theoretical foundation for linearly polarized PDs of low-dimensional perovskites.Beyond theoretical insights,the review also highlights cutting-edge fabrication techniques for one-dimensional nano wires and two-dimensional heterostructures,along with performance benchmarks of state-of-the-art devices.By integrating experimental advancements with theoretical insights,this work not only advances the fundamental understanding of polarization mechanisms but also outlines actionable pathways for optimizing device performance,stability,and scalability,which may serve as a critical resource for researchers aiming to harness the full potential of low-dimensional perovskites in polarized optoelectronics.
基金supported by the National University of Defense Technology Independent Innovation Science Fund(Nos.24-ZZCXJDZ-42 and XJJC2024088)Hefei Municipal Natural Science Foundation(No.K130936103)The authors extend their gratitude to Ms.Zhang from Scientific Compass(www.shiyanjia.com)for providing invaluable assistance.
文摘The growing complexity of electromagnetic(EM)interference has driven significant demand for next-generation absorbers that combine lightweight,flexibility,and good electromagnetic attenuation capability.The low-dimensional ternary Co_(3)ZnC/Co/CNT composites with hollow structures have been synthesized through in-situ polymerization and high-temperature carbonization.The unique integration of low-dimensional nanostructures and multicomponent heterointerfaces confers exceptional EM absorption properties,achieving a reflection loss of−70.0 dB and significantly reducing radar cross section(RCS)scattering signals.It is particularly meaningful that the numerical simulation of Co_(3)ZnC/Co/CNT metama-terial reveals ultrawideband absorption performance,achieving 10.7 GHz(7.3-18.0 GHz)at a thickness of 4.5 mm and extending to 15 GHz(3.0-18.0 GHz)with a 10.5 mm.Moreover,the Co_(3)ZnC/Co/CNT composites retain meritorious EM absorption properties after flexible film formation,broadening their usability and application scope.These investigations will provide seminal insights encompassing theoretical validation,experimental synthesis,and practical application for the next generation of absorbers.
基金financially supportsed by National Natural Science Foundation of China(No.52173150)Guangzhou Science and Technology Program City-University Joint Funding Project(No.2023A03J0001)Postdoctoral Science Foundation(No.2022M723670).
文摘Bacterial infections have always been a major threat to human health.Skin wounds are frequently exposed to the external environment,and they may become contaminated by bacteria derived from the surrounding skin,the local environment,and the patient’s own endogenous sources.Contaminated wounds may enter a state of chronic inflammation that impedes healing.Urgent development of antibacterial wound dressings capable of effectively combating bacteria and overcoming resistance is necessary.Nanotechnology and nanomaterials present promising potential as innovative strategies for antimicrobial wound dressings,owing to their robust antibacterial characteristics and the inherent advantage of avoiding antibiotic resistance.Therefore,this review provides a concise overview of the antimicrobial mechanisms exhibited by low-dimensional nanomaterials.It further categorizes common low-dimensional antimicrobial nanomaterials into zero-dimensional(0D),one-dimensional(1D)and two-dimensional(2D)nanomaterials based on their structural characteristics,and gives a detailed compendium of the latest research advances and applications of different low-dimensional antimicrobial nanomaterials in wound healing,which could be helpful for the development of more effective wound dressings.
基金This work was financially supported by the National Natural Science Foundation of China(Grant No.61622406,61571415,61625404,61888102)the National Key Research and Development Program of China(Grant No.2017YFA0207500,2016YFB0700700)+1 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB30000000)the Beijing Academy of Quantum Information Sciences(Grant No.Y18G04).
文摘Low-dimensional(including two-dimensional[2D],one-dimensional[1D],and zero-dimensional[0D])semiconductor materials have great potential in electronic/optoelectronic applications due to their unique structure and characteristics.Many 2D(such as transition metal dichalcogenides and black phosphorus)and 1D(such as NWs)materials have demonstrated superior performance in field effect transistors,photodetectors(PDs),and some flexible devices.And in some hybrid structures of 0D materials and 1D or 2D materials,the modification of 1D and 2D devices by 0D materials is embodied.This type of hybrid heterostructure has a larger performance optimization compared with the original.In the application of PDs,the variety of lowdimensional materials and properties enable wide-spectrum detection from ultraviolet UV to infrared,which provide a potential option for PDs under various conditions.For flexible electronic devices,high performance and mechanical stability are two important features.Low-dimensional materials offer unparalleled advantages in flexible devices.In this review,we will focus on the various low-dimensional materials that have been extensively studied and their applications in the electronics/optoelectronic and flexible electronics.From the composition and lattice structure of materials(including alloys)to the construction of various devices and heterostructures,we will introduce their application and recent development under various conditions.These works can provide valuable guidance for the construction and application of more highperformance and multifunctional devices.
基金supported by the Teli Fellowship from Beijing Institute of Technology,the National Natural Science Foundation of China(Nos.52303366,22173109).
文摘In recent years,low-dimensional transition metal chalcogenide(TMC)materials have garnered growing research attention due to their superior electronic,optical,and catalytic properties compared to their bulk counterparts.The controllable synthesis and manipulation of these materials are crucial for tailoring their properties and unlocking their full potential in various applications.In this context,the atomic substitution method has emerged as a favorable approach.It involves the replacement of specific atoms within TMC structures with other elements and possesses the capability to regulate the compositions finely,crystal structures,and inherent properties of the resulting materials.In this review,we present a comprehensive overview on various strategies of atomic substitution employed in the synthesis of zero-dimensional,one-dimensional and two-dimensional TMC materials.The effects of substituting elements,substitution ratios,and substitution positions on the structures and morphologies of resulting material are discussed.The enhanced electrocatalytic performance and photovoltaic properties of the obtained materials are also provided,emphasizing the role of atomic substitution in achieving these advancements.Finally,challenges and future prospects in the field of atomic substitution for fabricating low-dimensional TMC materials are summarized.
基金financially supported by Fundamental Research Funds for the Central Universities(Nos.10251210015,ZYTS23089 and 2020JCW-15)Guangdong Basic and Applied Basic Research Foundation(Nos.2021A1515110013 and 2021A1515110888)+1 种基金National Natural Science Foundation of China(Nos.22305182,51972204,22222505,21901195 and 22375121)Natural Science Basic Research Program of Shaanxi(Nos.2023-JCQN-0508 and 2023-JC-QN-0104)。
文摘Polarized-sensitive image sensors are a kind of photodetector with great development potential due to their enhanced ability to detect and identify the target objects from the aspect of spatial,spectral and polarized information.Recently,low-dimensional anisotropic materials with inherent anisotropic properties,ultrathin thickness,tunable bandgap and feasible integration with complementary metal oxide semiconductor(CMOS)fabrication processes have attracted great interest for their facilitation of polarized photodetector devices miniaturization.Maximizing the polarized detection performance of low-dimensional materials to satisfy realistic needs stimulates the exploration of modulation of anisotropic properties.In this review,we comprehensively introduce the latest research progress in modulating the optical and optoelectronic anisotropy characteristics of low-dimensional materials.The strategy of anisotropy regulation through crystal structure engineering and coupling system is discussed emphatically.Then,the latest progress in image recognition applications using anisotropic low-dimensional materials is reviewed in detail.Finally,we summarize the challenge and propose future opportunities in the practical application of polarized-sensitive imaging photodetectors based on low-dimensional anisotropic materials.
基金supported by the National Key Research and Development Program of China(2022YFB4200301)the National Natural Science Foundation of China(52202216)the Natural Science Foundation of Sichuan Province(24NSFSC1601).
文摘The use of low-dimensional(LD)perovskite materials is crucial for achieving high-performance perovskite solar cells(PSCs).However,LD perovskite films fabricated by conventional approaches give rise to full coverage of the underlying 3D perovskite films,which inevitably hinders the transport of charge carriers at the interface of PSCs.Here,we designed and fabricated LD perovskite structure that forms net-like morphology on top of the underlying three-dimensional(3D)perovskite bulk film.The net-like LD perovskite not only reduced the surface defects of 3D perovskite film,but also provided channels for the vertical transport of charge carriers,effectively enhancing the interfacial charge transfer at the LD/3D hetero-interface.The net-like morphological design comprising LD perovskite effectively resolves the contradiction between interfacial defect passivation and carrier extraction across the hetero-interfaces.Furthermore,the net-like LD perovskite morphology can enhance the stability of the underlying 3D perovskite film,which is attributed to the hydrophobic nature of LD perovskite.As a result,the net-like LD perovskite film morphology assists PSCs in achieving an excellent power conversion efficiency of up to 24.6%with over 1000 h long-term operational stability.
基金supported by the National Natural Science Foundation of China (52071237, 12074290, 51871169, 51671148, 11674251, 51601132, 52101021, and 12104345)the Natural Science Foundation of Jiangsu Province (BK20191187)+2 种基金the Fundamental Research Funds for the Central Universities (2042019kf0190)the Science and Technology Program of Shenzhen (JCYJ20190808150407522)the China Postdoctoral Science Foundation (2019M652685)。
文摘Metal oxide semiconductors(MOSs) are attractive candidates as functional parts and connections in nanodevices.Upon spatial dimensionality reduction, the ubiquitous strain encountered in physical reality may result in structural instability and thus degrade the performance of MOS. Hence, the basic insight into the structural evolutions of low-dimensional MOS is a prerequisite for extensive applications, which unfortunately remains largely unexplored. Herein, we review the recent progress regarding the mechanical deformation mechanisms in MOSs, such as CuO and ZnO nanowires(NWs). We report the phase transformation of CuO NWs resulting from oxygen vacancy migration under compressive stress and the tensile strain-induced phase transition in ZnO NWs. Moreover, the influence of electron beam irradiation on interpreting the mechanical behaviors is discussed.
基金supported by the National Natural Science Foundation of China(62374150)Natural Science Foundation of Henan(242300421216)+3 种基金C.Zheng acknowledges the support of China Postdoctoral Science Foundation(Grant No.2023TQ0296)the Postdoctoral Fellowship Program of CPSF(Grant No.GZC20232389)Y.Xie acknowledges the support of National Natural Science Foundation of China(62074011,62134008)Beijing Outstanding Young Scientist Program(JWZQ20240102009).
文摘Semiconductor optoelectronics devices,capable of converting electrical power into light or conversely light into electrical power in a compact and highly efficient manner represent one of the most advanced technologies ever developed,which has profoundly reshaped the modern life with a wide range of applications.In recent decades,semiconductor technology has rapidly evolved from first-generation narrow bandgap materials(Si,Ge)to the latest fourth-generation ultra-wide bandgap semiconductor(GaO,diamond,AlN)with enhanced performance to meet growing demands.Additionally,merging semiconductor devices with other techniques,such as computer assisted design,state-of-the-art micro/nano fabrications,novel epitaxial growth,have significantly accelerated the development of semiconductor optoelectronics devices.Among them,integrating metasurfaces with semiconductor optoelectronic devices have opened new frontiers for on-chip control of their electromagnetic response,providing access to previously inaccessible degrees of freedom.We review the recent advances in on-chip control of a variety of semiconductor optoelectronic devices using integrated metasurfaces,including semiconductor lasers,semiconductor light emitting devices,semiconductor photodetectors,and low dimensional semiconductors.The integration of metasurfaces with semiconductors offers wafer-level ultracompact solutions for manipulating the functionalities of semiconductor devices,while also providing a practical platform for implementing cuttingedge metasurface technology in real-world applications.
基金Supported by Bissell Distinguished Professor Endowment Fund at UNC-Charlotte。
文摘Although there are numerous optical spectroscopy techniques and methods that have been used to extract the fundamental bandgap of a semiconductor,most of them belong to one of these three approaches:(1)the excitonic absorption,(2)modulation spectroscopy,and(3)the most widely used Tauc-plot.The excitonic absorption is based on a many-particle theory,which is physically the most correct approach,but requires more stringent crystalline quality and appropriate sample preparation and experimental implementation.The Tauc-plot is based on a single-particle theo⁃ry that neglects the many-electron effects.Modulation spectroscopy analyzes the spectroscopy features in the derivative spectrum,typically,of the reflectance and transmission under an external perturbation.Empirically,the bandgap ener⁃gy derived from the three approaches follow the order of E_(ex)>E_(MS)>E_(TP),where three transition energies are from exci⁃tonic absorption,modulation spectroscopy,and Tauc-plot,respectively.In principle,defining E_(g) as the single-elec⁃tron bandgap,we expect E_(g)>E_(ex),thus,E_(g)>E_(TP).In the literature,E_(TP) is often interpreted as E_(g),which is conceptual⁃ly problematic.However,in many cases,because the excitonic peaks are not readily identifiable,the inconsistency be⁃tween E_(g) and E_(TP) becomes invisible.In this brief review,real world examples are used(1)to illustrate how excitonic absorption features depend sensitively on the sample and measurement conditions;(2)to demonstrate the differences between E_(ex),E_(MS),and E_(TP) when they can be extracted simultaneously for one sample;and(3)to show how the popular⁃ly adopted Tauc-plot could lead to misleading results.Finally,it is pointed out that if the excitonic absorption is not ob⁃servable,the modulation spectroscopy can often yield a more useful and reasonable bandgap than Tauc-plot.
文摘Radiation doses to patients in diagnostics and interventional radiology need to be optimized to comply with the principles of radiation protection in medical practice. This involves using specific detectors with respective diagnostic beams to carry out quality control/quality assurance tests needed to optimize patient doses in the hospital. Semiconductor detectors are used in dosimetry to verify the equipment performance and dose to patients. This work aims to assess the performance, energy dependence, and response of five commercially available semiconductor detectors in RQR, RQR-M, RQA, and RQT at Secondary Standard Dosimetry for clinical applications. The diagnostic beams were generated using Exradin A4 reference ion chamber and PTW electrometer. The ambient temperature and pressure were noted for KTP correction. The detectors designed for RQR showed good performance in RQT beams and vice versa. The detectors designed for RQR-M displayed high energy dependency in other diagnostic beams. The type of diagnostic beam quality determines the response of semiconductor detectors. Therefore, a detector should be calibrated according to the beam qualities to be measured.
基金National Natural Science Foundation of China(12002196,12102140)。
文摘Semiconductors and related fields today hold vast application prospects.The semiconductor wafer fabrication process involves steps such as substrate preparation and epitaxy,which occur in high-temperature corrosive environments.Consequently,components like crucibles,susceptors and wafer carriers require carbon-based materials such as graphite and carbon-carbon composites.However,traditional carbon materials underperform in these extreme conditions,failing to effectively address the challenges.This leads to issues including product contamination and shortened equipment lifespan.Therefore,effective protection of carbon materials is crucial.This paper reviews current research status on the preparation methods and properties of corrosion-resistant coatings within relevant domestic and international fields.Preparation methods include various techniques such as physical vapor deposition(PVD),chemical vapor deposition(CVD)and the sol-gel method.Furthermore,it offers perspectives on future research directions for corrosion-resistant coated components in semiconductor equipment.These include exploring novel coating materials,improving coating preparation processes,enhancing coating corrosion resistance,as well as further investigating the interfacial interactions between coatings and carbon substrates to achieve better adhesion and compatibility.
基金Supported by the National Key Research and Development Program of China(2021YFB2012601)National Natural Science Foundation of China(12204109)+1 种基金Science and Technology Innovation Plan of Shanghai Science and Technology Commission(21JC1400200)Higher Education Indus⁃try Support Program of Gansu Province(2022CYZC-06)。
文摘Organic semiconductor materials have shown unique advantages in the development of optoelectronic devices due to their ease of preparation,low cost,lightweight,and flexibility.In this work,we explored the application of the organic semiconductor Y6-1O single crystal in photodetection devices.Firstly,Y6-1O single crystal material was prepared on a silicon substrate using solution droplet casting method.The optical properties of Y6-1O material were characterized by polarized optical microscopy,fluorescence spectroscopy,etc.,confirming its highly single crystalline performance and emission properties in the near-infrared region.Phototransistors based on Y6-1O materials with different thicknesses were then fabricated and tested.It was found that the devices exhibited good visible to near-infrared photoresponse,with the maximum photoresponse in the near-infrared region at 785 nm.The photocurrent on/off ratio reaches 10^(2),and photoresponsivity reaches 16 mA/W.It was also found that the spectral response of the device could be regulated by gate voltage as well as the material thickness,providing important conditions for optimizing the performance of near-infrared photodetectors.This study not only demonstrates the excellent performance of organic phototransistors based on Y6-1O single crystal material in near-infrared detection but also provides new ideas and directions for the future development of infrared detectors.
基金supported by the National Key R&D Program of China(Grant No.2022YFA1405100)Chinese Academy of Sciences Project for Young Scientists in Basic Research(Grant No.YSBR-030)+3 种基金the Basic Research Program of the Chinese Academy of Sciences Based on Major Scientific Infrastructures(Grant No.JZHKYPT-2021-08)GS was supported in part by the Innovation Program for Quantum Science and Technology(Grant No.2024ZD03005)the National Natural Science Foundation of China(Grant No.12447101)Chinese Academy of Sciences.
文摘Realizing ferromagnetic semiconductors with high Curie temperature TC is still a challenge in spintronics.Recent experiments have reported two-dimensional(2D)room temperature ferromagnetic metals,such as monolayer Cr_(3)Te_(6).In this paper,through density functional theory(DFT)calculations,we propose a method to obtain 2D high TC ferromagnetic semiconductors through element replacement in these ferromagnetic metals.We predict that monolayer(Cr_(4/6),Mo_(2/6))_(3)Te_(6),created via element replacement in monolayer Cr_(3)Te_(6),is a room-temperature ferromagnetic semiconductor exhibiting a band gap of 0.34 eV and a TC of 384 K.Our analysis reveals that the metal-to-semiconductor transition stems from the synergistic interplay of Mo-induced lattice distortion,which resolves band overlap,and the electronic contributions of Mo dopants,which further drive the formation of a distinct band gap.The origin of the high TC is traced to strong superexchange coupling between magnetic ions,analyzed via the superexchange model with DFT and Wannier function calculations.Considering the fast developments in fabrication and manipulation of 2D materials,our theoretical results propose an approach to explore high-temperature ferromagnetic semiconductors derived from experimentally obtained 2D high-temperature ferromagnetic metals through element replacement.
文摘All-inorganic CsPbBr_(3) perovskite quantum dots(QDs)have attracted extensive attention in photoelectric detection for their excellent photoelectric properties and stability.However,the CsPbBr_(3) quantum dot film exhibits a high non-radiative recombination rate,and the mismatch in energy levels with the carbon electrode weakens hole extraction efficiency.These reduces the device's performance.To improve this,a semiconductor photodetector based on fluorine-doped tin oxide(FTO)/dense titanium dioxide(c-TiO_(2))/mesoporous titanium dioxide(m-TiO_(2))/CsPbBr_(3) QDs/CsPbBr_(x)I_(3-x)(x=2,1.5,1)QDs/C struc-ture was studied.By adjusting the Br-:I-ratio,the synthesized CsPbBr_(x)I_(3-x)(x=2,1.5,1)QDs showed an adjustable band gap width of 2.284-2.394 eV.And forming a typeⅡband structure with CsPbBr_(3) QDs,which reduced the valence band offset between the active layer and the carbon electrode,this promoted carrier extraction and reduced non-radiative recombination rate.Compared with the original device(the photosensitive layer is CsPbBr_(3) QDs),the performance of the photodetector based on the CsPbBr_(3) QDs/CsPbBr2I QDs heterostructure is significantly improved,the responsivity(R)increased by 73%,the specific detectivity rate(D^(*))increased from 6.98×10^(12) to 3.19×10^(13) Jones,the on/off ratio reached 106.This study provides a new idea for the development of semiconductor tandem detectors.
基金financially supported by the Program of the National Natural Science Foundation of China(Grant No.52371055)the Young Elite Scientist Sponsorship Program Cast(Grant No.YESS20200139)the Basic Scientific Research Project of Liaoning Provincial Department of Education(Grant No.JYTMS20230618)。
文摘The effect of intermetallic particles on the corrosion of 6061 aluminum alloy and its coating used in semiconductor processing systems was systematically studied via liquid and gas experiments and micromorphology characterization.The results revealed that a huge difference of corrosion resistance between imported and domestic 6061 aluminum alloys in HCl solution and gas acid mist experiments mainly was attributed to the different size and amount of Al_(15)(Fe,Mn)_(3)Si_(2).The corrosion resistance of domestic 6061 alloy in dry/wet semiconductor electronic special gas environments was worse than that of imported aluminum alloy,and there are great differences in the corrosion mechanism of 6061 alloy caused by the second phase in the two dry/wet environments.And the corrosion resistance of the hard anodized alumina film was closely related to the microscopic morphology of holes.The vertical and elongatedα-Al_(15)(Mn,Fe)_(3)Si_(2) phase was formed in the rolled aluminum alloy that has been rolled perpendicular to the surface of the substrate.Compared to the horizontal long hole,the longitudinal long holes generated by the verticalα-Al_(15)(Mn,Fe)_(3)Si_(2) phase will enable the corrosive medium to reach the substrate rapidly,which significantly weakens the corrosion resistance of the hard anodized film.
基金supported by the National Key Research and Development Program of China(Grant Nos.2022YFA1402701 and 2022YFA1403202)the National Natural Science Foundation of China(Grant No.12074333)the Key Research and Development Program of Zhejiang Province,China(Grant No.2021C01002)。
文摘We report the manipulation of ferromagnetism in magnetic semiconductor Ba(Zn,Mn,Cu)_(2)As_(2)through chemical pressure.The substitutions of Sr for Ba and Sb for As introduce positive and negative chemical pressures,respectively;neither Sr doping nor Sb doping change the tetragonal crystal structure.Based on Ba(Zn_(0.75)Mn_(0.125)Cu_(0.125))_(2)As_(2)with T_(C)~34 K,10%Sr/Ba substitutions significantly improve T_(C)by~15%to 39 K,whereas 10%Sb/As substitutions substantially reduce TCby~47%to 18 K.The AC magnetic susceptibility measurements indicate that Sr-doped and Sb-doped samples evolve into a spin glass state below the spin freezing temperature Tf.Electrical transport measurements demonstrate that Sr-doped specimens retain semiconducting behavior;additionally,they display a significant negative magnetoresistance effect under applied magnetic fields and the magnetoresistance reaches~-19%at 8 T.
基金supported by the National Natural Science Foundation of China(Grant Nos.52272219 and U1904612)the Natural Science Foundation of Henan Province(Grant No.242300421191).
文摘TiO_(2)is a well-known photocatalyst with a band gap of 3.2 eV,yet its ability to absorb light is limited to the short wavelengths of ultraviolet light.To achieve a more effective photocatalytic material,we have designed two-dimensional semiconductor TiOS materials using swarm intelligence algorithms combined with first-principles calculations.Three stable low-energy structures with space groups of P2_(1)/m,P3m1 and P2_(1)/c are identified.Among these structures,the Janus P3m1 phase is a direct bandgap semiconductor,while the P2_(1)/m and P2_(1)/c phases are indirect bandgap semiconductors.Utilizing the accurate hybrid density functional HSE06 method,the band gaps of the three structures are calculated to be 2.34 eV(P2_(1)/m),2.24 eV(P3m1)and 3.22 eV(P2_(1)/c).Optical calculations reveal that TiOS materials exhibit a good light-harvesting capability in both visible and ultraviolet spectral ranges.Moreover,the photocatalytic calculations also indicate that both P2_(1)/m and P3m1 TiOS can provide a strong driving force for converting H_(2)O to H_(2)and O_(2)in an acidic environment with pH=0.The structural stabilities,mechanical properties,electronic structures and hydrogen evolution reaction activities are also discussed in detail.Our research suggests that two-dimensional TiOS materials have potential applications in both semiconductor devices and photocatalysis.
