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
Topological superconductor islands are thought to be the building blocks of topological quantum bits.We produced single-crystalline VSi_(x)islands with well-defined side facets and island size more than 200nm using mo...Topological superconductor islands are thought to be the building blocks of topological quantum bits.We produced single-crystalline VSi_(x)islands with well-defined side facets and island size more than 200nm using molecular beam epitaxy on Si substrate heated to 950℃throughout the growth process.By means of scanning tunneling spectroscopy,we revealed dynamical Coulomb blockade and superconductivity on isolated islands and on islands being connected by superconducting wetting layer respectively.Bi_(2)Te_(3)films were further deposited on VSi_(x)islands.Robust and homogenous proximity effect induced superconductivity was observed on various facets of the Bi_(2)Te_(3)/VSi_(x)hetero-nanostructure.Furthermore,our high-resolution spectroscopy identified Bosonic mode excitations on the topological superconductor islands.These results may establish a playground for the vortex Majorana islands.展开更多
The kagome lattice,characterized by a hexagonal arrangement of corner-sharing equilateral triangles,has garnered significant attention as a fascinating quantum material system that hosts exotic magnetic and electronic...The kagome lattice,characterized by a hexagonal arrangement of corner-sharing equilateral triangles,has garnered significant attention as a fascinating quantum material system that hosts exotic magnetic and electronic properties.The identification and characterization of this class of materials are critical for advancing our understanding of their role in emergent phenomena such as superconductivity.In this study,we developed a high-throughput screening framework for the systematic identification and classification of superconducting materials with kagome lattices,integrating them into established materials databases.Leveraging the Materials Project(MP)database and the MDR Super Con dataset,we analyzed over 150000 inorganic compounds and cross-referenced 26000 known superconductors.Using geometry-based structural modeling and experimental validation,we identified 129 kagome superconductors belonging to 17 distinct structural families,many of which had not previously been recognized as kagome systems.The materials are further classified into three categories in terms of topological flat bands,clean band structures,and coexisting magnetic or charge density wave(CDW)orderings.Based on these results,we established a database comprising 129 kagome superconductors,including the detailed crystallographic,electronic,and superconducting properties of these materials.展开更多
The discovery of high-temperature superconducting materials holds great significance for human industry and daily life.In recent years,research on predicting superconducting transition temperatures using artificial in...The discovery of high-temperature superconducting materials holds great significance for human industry and daily life.In recent years,research on predicting superconducting transition temperatures using artificial intelligence(AI)has gained popularity,with most of these tools claiming to achieve remarkable accuracy.However,the lack of widely accepted benchmark datasets in this field has severely hindered fair comparisons between different AI algorithms and impeded further advancement of these methods.In this work,we present HTSC-2025,an ambient-pressure high-temperature superconducting benchmark dataset.This comprehensive compilation encompasses theoretically predicted superconducting materials discovered by theoretical physicists from 2023 to 2025 based on BCS superconductivity theory,including the renowned X_(2)YH_(6)system,perovskite MXH_(3)system,M_(3)H_(8)system,cage-like BCN-doped metal atomic systems derived from LaH_(10)structural evolution,and two-dimensional honeycomb-structured systems evolving from MgB_(2).In addition,we note a range of approaches inspired by physical intuition for designing high-temperature superconductors,such as hole doping,the introduction of light elements to form strong covalent bonds,and the tuning of spin-orbit coupling.The dataset presented in this paper is openly available at Science DB.The HTSC-2025 benchmark has been open-sourced on Hugging Face at https://huggingface.co/datasets/xiao-qi/HTSC-2025 and will be continuously updated,while the Electronic Laboratory for Material Science platform is available at https://in.iphy.ac.cn/eln/link.html#/124/V2s4.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
The kagome lattice,naturally encompassing Dirac fermions,flat bands,and van Hove singularities,tends to intertwine exotic electronic states.Revealing the characteristics of its Fermi surface will help clarify the natu...The kagome lattice,naturally encompassing Dirac fermions,flat bands,and van Hove singularities,tends to intertwine exotic electronic states.Revealing the characteristics of its Fermi surface will help clarify the nature of the complex quantum phenomena in kagome material.Here we report the Fermi surface properties of the novel kagome metal CsTi_(3)Bi_(5)by the de Haas-van Alphen oscillations.The observed oscillations are clear and consist of six principal frequencies ranging from 214 T to 1013 T.The angular dependence of the frequency implies a quasi-two-dimensional electronic structure.In addition,the geometry phase corresponding to 281 T,determined by direct Lifshitz-Kosevich formula fitting,yields a value close toπ,which may indicate a band structure with nontrivial topological property.These results underscore the potential of CsTi_(3)Bi_(5)as a promising platform to explore the interplay between topological order,electronic nematicity,and superconductivity.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
The electron-doped cuprate superconductor exhibits a unique electronic structure,where both electron and hole Fermi surface(FS)pockets coexist in the optimally doped(OP)region,while in the overdoped(OD)region there ex...The electron-doped cuprate superconductor exhibits a unique electronic structure,where both electron and hole Fermi surface(FS)pockets coexist in the optimally doped(OP)region,while in the overdoped(OD)region there exists only a large hole FS pocket.It is therefore an intriguing question whether or not a p-n junction arises if the OD electron-doped cuprate interfaces with the OP compound.Here,we construct such an in-plane junction by selectively modulating the doping levels in thin films of La_(2-x)Ce_(x)CuO_(4)(LCCO)—a typical electron-doped cuprate.We find that the junction exhibits non-linear,asymmetricⅠ-Ⅴcharacteristics,which are consistent with those of a p-n semiconductor junction,across a wide temperature range from 250 K to 10 K,regardless of the Hall coefficient sign change or the superconducting transition.We attribute these features to a potential barrier formed at the junction,which is set by the band bending in both OD and OP LCCO.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
Iron-based superconductors(FeSCs)feature a complex phase diagram,and their diverse cleavage terminations offer a versatile platform for modulating surface electronic states and investigating the underlying superconduc...Iron-based superconductors(FeSCs)feature a complex phase diagram,and their diverse cleavage terminations offer a versatile platform for modulating surface electronic states and investigating the underlying superconducting mechanisms.In this study,we explore the surface modulation of KCa_(2)Fe_(4)As_(4)F_(2)using scanning tunneling microscopy/spectroscopy.Cryogenically cleaved surfaces reveal multiple configurations,including√2×√2 reconstruction,1×2 and 1×3 stripes,as well as nanoscale vacancies.Reducing potassium coverage induces hole doping,which shifts the density of states peak toward the Fermi level and suppresses the superconducting gap from 4.8 meV to 3.2 meV.This behavior is reminiscent of the Van Hove singularity observed in hole-doped 122-type FeSCs.The band structure does not undergo a simple rigid shift,and the evolution of superconductivity can be attributed to the interplay between surface carriers and electronic correlations.Additionally,a V-shaped gap is observed at a unique location preserving the FeAs bilayer structure,where interlayer coupling effects are likely involved.The diversity of surface structures and electronic states in K12442 enhances our understanding of FeSCs and facilitates the modulation and application of FeAs superconducting layers.展开更多
Exploring novel superconductors is a crucial topic in condensed matter physics.There are few reports on the superconductivity of fluorine due to the extremely high pressures required for its metallization.Here,metalli...Exploring novel superconductors is a crucial topic in condensed matter physics.There are few reports on the superconductivity of fluorine due to the extremely high pressures required for its metallization.Here,metallization and superconductivity of fluorine were achieved in MgF_(5)at 120 GPa by exploiting the high-pressure s-d transition of doped Mg.The unexpected Mg-F covalent bonding induced by Mg-d and F-p orbital interactions led to fluorine metallization and the formation of an F skeleton similar to a H-cage.The high density of states(DOS)from the F skeleton and phonon softening from strong Fermi surface nesting contribute to a high superconducting transition temperature(Tc).The Tc of Pmmm-MgF_(5)at 120 GPa is 14.02 K,with strong electron-phonon coupling(λ=0.84),which is close to that of Li_(6)P at 270 GPa(λ=1.01).This is the first observation of superconductivity in main-group metal fluorides.Additionally,two near-monatomic F atoms exist in the interstitial region of MgF_(5),significantly enhancing electron-phonon coupling.This work challenges the traditional view of main-group metal fluorides and provides deeper insights into the superconductivity and physicochemical properties of fluorine.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
The fracture mechanics theory posits that cracks induce strain energy concentration near their tips in structural components,generating localized flexibility that impedes crack propagation.Theoretically,cracks are rep...The fracture mechanics theory posits that cracks induce strain energy concentration near their tips in structural components,generating localized flexibility that impedes crack propagation.Theoretically,cracks are represented as dimensionless,massless spring models,effectively capturing crack characteristics and cross-sectional properties at the crack location.Leveraging this spring-based representation,this study establishes an open-crack model for a one-dimensional(1D)piezoelectric semiconductor(PSC)curved beam under dynamic loading.This model enables the investigation of vibration characteristics in cracked structures.The analytical solutions for the electromechanical fields of the beam are derived using the differential operator method,and the natural frequencies together with the corresponding generalized mode shapes of the beam are determined analytically.Furthermore,the effects of the crack parameters on the natural vibration characteristics of the PSC curved beam are analyzed.展开更多
A principle was proposed for designing a method to seal anodized aluminum used in semiconductor processing apparatuses.Thermodynamic calculations and Fick’s second law were used to reveal trends in the metal ion depo...A principle was proposed for designing a method to seal anodized aluminum used in semiconductor processing apparatuses.Thermodynamic calculations and Fick’s second law were used to reveal trends in the metal ion deposition,deposition product stability,vapor pressures of halides for selected metal ions,the holding temperature,and time.Interactions between ion concentrations and the sealing temperature were also revealed.According to the design principles,anodized aluminum dipped in 1 mM Cr^(3+)ion solution and steam-sealed for 18 h exhibited the highest corrosion resistance when exposed to 5 wt.%HCl solution and HCl gas,verifying the designed results.展开更多
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 Natural Science Foundation of China(Grant Nos.92365302,92065201,12488101,22325203,92265105,12074247,12174252,and 52102336)the Ministry of Science and Technology of China(Grant Nos.2019YFA0308600 and 2020YFA0309000)+1 种基金the Science and Technology Commission of Shanghai Municipality(Grant Nos.2019SHZDZX01,19JC1412701,20QA1405100,24LZ1401000,and LZPY2024-04)the financial support from Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302500)。
文摘Topological superconductor islands are thought to be the building blocks of topological quantum bits.We produced single-crystalline VSi_(x)islands with well-defined side facets and island size more than 200nm using molecular beam epitaxy on Si substrate heated to 950℃throughout the growth process.By means of scanning tunneling spectroscopy,we revealed dynamical Coulomb blockade and superconductivity on isolated islands and on islands being connected by superconducting wetting layer respectively.Bi_(2)Te_(3)films were further deposited on VSi_(x)islands.Robust and homogenous proximity effect induced superconductivity was observed on various facets of the Bi_(2)Te_(3)/VSi_(x)hetero-nanostructure.Furthermore,our high-resolution spectroscopy identified Bosonic mode excitations on the topological superconductor islands.These results may establish a playground for the vortex Majorana islands.
基金supported by the National Key Research and Development Program of China(Grant No.2018YFE0202600)the National Natural Science Foundation of China(Grant No.52272268)+3 种基金the Key Research Program of Frontier SciencesCAS(Grant No.QYZDJ-SSWSLH013)the Informatization Plan of Chinese Academy of Sciences(Grant No.CAS-WX2021SF-0102)the Youth Innovation Promotion Association of CAS(Grant No.2019005)。
文摘The kagome lattice,characterized by a hexagonal arrangement of corner-sharing equilateral triangles,has garnered significant attention as a fascinating quantum material system that hosts exotic magnetic and electronic properties.The identification and characterization of this class of materials are critical for advancing our understanding of their role in emergent phenomena such as superconductivity.In this study,we developed a high-throughput screening framework for the systematic identification and classification of superconducting materials with kagome lattices,integrating them into established materials databases.Leveraging the Materials Project(MP)database and the MDR Super Con dataset,we analyzed over 150000 inorganic compounds and cross-referenced 26000 known superconductors.Using geometry-based structural modeling and experimental validation,we identified 129 kagome superconductors belonging to 17 distinct structural families,many of which had not previously been recognized as kagome systems.The materials are further classified into three categories in terms of topological flat bands,clean band structures,and coexisting magnetic or charge density wave(CDW)orderings.Based on these results,we established a database comprising 129 kagome superconductors,including the detailed crystallographic,electronic,and superconducting properties of these materials.
基金supported by the National Natural Science Foundation of China(Grant Nos.62476278,12434009,12204533)the National Key R&D Program of China(Grant No.2024YFA1408601)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302402)。
文摘The discovery of high-temperature superconducting materials holds great significance for human industry and daily life.In recent years,research on predicting superconducting transition temperatures using artificial intelligence(AI)has gained popularity,with most of these tools claiming to achieve remarkable accuracy.However,the lack of widely accepted benchmark datasets in this field has severely hindered fair comparisons between different AI algorithms and impeded further advancement of these methods.In this work,we present HTSC-2025,an ambient-pressure high-temperature superconducting benchmark dataset.This comprehensive compilation encompasses theoretically predicted superconducting materials discovered by theoretical physicists from 2023 to 2025 based on BCS superconductivity theory,including the renowned X_(2)YH_(6)system,perovskite MXH_(3)system,M_(3)H_(8)system,cage-like BCN-doped metal atomic systems derived from LaH_(10)structural evolution,and two-dimensional honeycomb-structured systems evolving from MgB_(2).In addition,we note a range of approaches inspired by physical intuition for designing high-temperature superconductors,such as hole doping,the introduction of light elements to form strong covalent bonds,and the tuning of spin-orbit coupling.The dataset presented in this paper is openly available at Science DB.The HTSC-2025 benchmark has been open-sourced on Hugging Face at https://huggingface.co/datasets/xiao-qi/HTSC-2025 and will be continuously updated,while the Electronic Laboratory for Material Science platform is available at https://in.iphy.ac.cn/eln/link.html#/124/V2s4.
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.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2022YFA1403903,2023YFA1406100,2018YFA0305800,and 2022YFA1204100)the National Natural Science Foundation of China(Grant Nos.12304075,11834014,61888102,and 12447101)+2 种基金Chinese Academy of Sciences(Grant Nos.XDB33010200 and 2022YSBR-048)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB28000000)the National Science and Technology Major Project(Grant No.2024ZD0300500)。
文摘The kagome lattice,naturally encompassing Dirac fermions,flat bands,and van Hove singularities,tends to intertwine exotic electronic states.Revealing the characteristics of its Fermi surface will help clarify the nature of the complex quantum phenomena in kagome material.Here we report the Fermi surface properties of the novel kagome metal CsTi_(3)Bi_(5)by the de Haas-van Alphen oscillations.The observed oscillations are clear and consist of six principal frequencies ranging from 214 T to 1013 T.The angular dependence of the frequency implies a quasi-two-dimensional electronic structure.In addition,the geometry phase corresponding to 281 T,determined by direct Lifshitz-Kosevich formula fitting,yields a value close toπ,which may indicate a band structure with nontrivial topological property.These results underscore the potential of CsTi_(3)Bi_(5)as a promising platform to explore the interplay between topological order,electronic nematicity,and superconductivity.
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Project supported by the National Key Research and Development Program of China(Grant No.2022YFA1403100)the National Natural Science Foundation of China(Grant Nos.52388201,12361141820,and 12274249)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302400)。
文摘The electron-doped cuprate superconductor exhibits a unique electronic structure,where both electron and hole Fermi surface(FS)pockets coexist in the optimally doped(OP)region,while in the overdoped(OD)region there exists only a large hole FS pocket.It is therefore an intriguing question whether or not a p-n junction arises if the OD electron-doped cuprate interfaces with the OP compound.Here,we construct such an in-plane junction by selectively modulating the doping levels in thin films of La_(2-x)Ce_(x)CuO_(4)(LCCO)—a typical electron-doped cuprate.We find that the junction exhibits non-linear,asymmetricⅠ-Ⅴcharacteristics,which are consistent with those of a p-n semiconductor junction,across a wide temperature range from 250 K to 10 K,regardless of the Hall coefficient sign change or the superconducting transition.We attribute these features to a potential barrier formed at the junction,which is set by the band bending in both OD and OP LCCO.
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 Key Research and Development Program of China(Grant Nos.2024YFA1611103 and 2022YFA1403203)the Innovation Program for Quantum Science and Technology(Grant Nos.2024ZD0301300 and 2021ZD0302802)the National Natural Science Foundation of China(Grant Nos.12474128,12374133,12204008,and 12104004)。
文摘Iron-based superconductors(FeSCs)feature a complex phase diagram,and their diverse cleavage terminations offer a versatile platform for modulating surface electronic states and investigating the underlying superconducting mechanisms.In this study,we explore the surface modulation of KCa_(2)Fe_(4)As_(4)F_(2)using scanning tunneling microscopy/spectroscopy.Cryogenically cleaved surfaces reveal multiple configurations,including√2×√2 reconstruction,1×2 and 1×3 stripes,as well as nanoscale vacancies.Reducing potassium coverage induces hole doping,which shifts the density of states peak toward the Fermi level and suppresses the superconducting gap from 4.8 meV to 3.2 meV.This behavior is reminiscent of the Van Hove singularity observed in hole-doped 122-type FeSCs.The band structure does not undergo a simple rigid shift,and the evolution of superconductivity can be attributed to the interplay between surface carriers and electronic correlations.Additionally,a V-shaped gap is observed at a unique location preserving the FeAs bilayer structure,where interlayer coupling effects are likely involved.The diversity of surface structures and electronic states in K12442 enhances our understanding of FeSCs and facilitates the modulation and application of FeAs superconducting layers.
基金supported by the National Natural Science Foundation of China(Nos.12374004 and 12174141)the National Key R&D Program of China(No.2023YFA1406200)。
文摘Exploring novel superconductors is a crucial topic in condensed matter physics.There are few reports on the superconductivity of fluorine due to the extremely high pressures required for its metallization.Here,metallization and superconductivity of fluorine were achieved in MgF_(5)at 120 GPa by exploiting the high-pressure s-d transition of doped Mg.The unexpected Mg-F covalent bonding induced by Mg-d and F-p orbital interactions led to fluorine metallization and the formation of an F skeleton similar to a H-cage.The high density of states(DOS)from the F skeleton and phonon softening from strong Fermi surface nesting contribute to a high superconducting transition temperature(Tc).The Tc of Pmmm-MgF_(5)at 120 GPa is 14.02 K,with strong electron-phonon coupling(λ=0.84),which is close to that of Li_(6)P at 270 GPa(λ=1.01).This is the first observation of superconductivity in main-group metal fluorides.Additionally,two near-monatomic F atoms exist in the interstitial region of MgF_(5),significantly enhancing electron-phonon coupling.This work challenges the traditional view of main-group metal fluorides and provides deeper insights into the superconductivity and physicochemical properties of fluorine.
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.
基金supported by the National Natural Science Foundation of China(No.12272353)the Postdoctoral Research Grant in Henan Province of China(No.202003091)the Key Scientific Research Projects in Colleges and Universities of Henan Province of China(No.22A130008)。
文摘The fracture mechanics theory posits that cracks induce strain energy concentration near their tips in structural components,generating localized flexibility that impedes crack propagation.Theoretically,cracks are represented as dimensionless,massless spring models,effectively capturing crack characteristics and cross-sectional properties at the crack location.Leveraging this spring-based representation,this study establishes an open-crack model for a one-dimensional(1D)piezoelectric semiconductor(PSC)curved beam under dynamic loading.This model enables the investigation of vibration characteristics in cracked structures.The analytical solutions for the electromechanical fields of the beam are derived using the differential operator method,and the natural frequencies together with the corresponding generalized mode shapes of the beam are determined analytically.Furthermore,the effects of the crack parameters on the natural vibration characteristics of the PSC curved beam are analyzed.
基金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)+1 种基金the Basic Scientific Research Project of Liaoning Provincial Department of Education(Grant No.JYTMS20230618)Special thanks are due to the instrumental analysis from the Analytical and Testing Centre,Northeastern University.
文摘A principle was proposed for designing a method to seal anodized aluminum used in semiconductor processing apparatuses.Thermodynamic calculations and Fick’s second law were used to reveal trends in the metal ion deposition,deposition product stability,vapor pressures of halides for selected metal ions,the holding temperature,and time.Interactions between ion concentrations and the sealing temperature were also revealed.According to the design principles,anodized aluminum dipped in 1 mM Cr^(3+)ion solution and steam-sealed for 18 h exhibited the highest corrosion resistance when exposed to 5 wt.%HCl solution and HCl gas,verifying the designed results.
