Zinc oxide(ZnO),as a broadband gap semiconductor material,exhibits unique physical and chemical properties that make it highly suitable for optoelectronics,piezoelectric devices,and gas-sensitive sensors,showing signi...Zinc oxide(ZnO),as a broadband gap semiconductor material,exhibits unique physical and chemical properties that make it highly suitable for optoelectronics,piezoelectric devices,and gas-sensitive sensors,showing significant potential for various applications.This paper focuses on the regulation and application of ZnO-based p-n junctions and piezoelectric devices.It discusses in detail the preparation of ZnO materials,the construction of p-n junctions,the optimization of piezoelectric device performance,and its application in various fields.By employing different preparation methods and strategies,high-quality ZnO thin films can be grown,and effective control of p-type conductivity achieved.This study provides both a theoretical foundation and technical support for controlling the performance of ZnO-based piezoelectric devices,as well as paving new pathways for the broader application of ZnO materials.展开更多
The p-n junction is the foundation building structure for manufacturing various electronic and optoelec-tronic devices.Ultrawide bandgap semiconductors are expected to overcome the limited power capability of Si-based...The p-n junction is the foundation building structure for manufacturing various electronic and optoelec-tronic devices.Ultrawide bandgap semiconductors are expected to overcome the limited power capability of Si-based electronic device,however,it is very difficult to achieve efficient bipolar doping due to the asymmetric doping effect,thereby impeding the development of p-n homojunction and related bipolar devices,especially for the Ga_(2)O_(3)-based materials and devices.Here,we demonstrate a unique one-step integrated growth of p-type N-doped(201)β-Ga_(2)O_(3)/n-type Si-doped(¯201)β-Ga_(2)O_(3)films by phase tran-sition and in-situ pre-doping of dopants,and fabrication of fullβ-Ga_(2)O_(3)linearly-graded p-n homojunc-tion diode from them.The fullβ-Ga_(2)O_(3)p-n homojunction diode possesses a large built-in potential of 4.52 eV,a high operation electric field>2.90 MV/cm in the reverse-bias regime,good longtime-stable rectifying behaviors with a rectification ratio of 104,and a high-speed switching and good surge robust-ness with a weak minority-carrier charge storage.Our work opens the way to the fabrication of Ga_(2)O_(3)-based p-n homojunction,lays the foundation for fullβ-Ga_(2)O_(3)-based bipolar devices,and paves the way for the novel fabrication of p-n homojunction for wide-bandgap oxides.展开更多
Polycrystalline diamond thin films are deposited on an n-type Si substrates by hot filament chemical vapor deposition,and then are implanted with boron ions in a 200keV ion implanter.In order to achieve a better distr...Polycrystalline diamond thin films are deposited on an n-type Si substrates by hot filament chemical vapor deposition,and then are implanted with boron ions in a 200keV ion implanter.In order to achieve a better distribution of the implanted element,boron ions are implanted by two steps:implanting boron ions with the energy of 70keV first,and then with the energy of 100keV.The homogeneous distribution of the B ion is gained.The current-voltage characteristics of the samples are studied.It is found that the p-n heterojunction effect is achieved in these samples.展开更多
Single event transient of a real p-n junction in a 0.18μm bulk process is studied by 3D TCAD simulation. The impact of voltage, temperature, substrate concentration, and LET on SET is studied. Our simulation results ...Single event transient of a real p-n junction in a 0.18μm bulk process is studied by 3D TCAD simulation. The impact of voltage, temperature, substrate concentration, and LET on SET is studied. Our simulation results demonstrate that biases in the range 1.62 to 1.98V influence DSET current shape greatly and total collected charge weakly. Peak current and charge collection within 2ns decreases as temperature increases,and temperature has a stronger influence on SET currents than on total charge. Typical variation of substrate concentration in modern VDSM processes has a negligible effect on SEEs. Both peak current and total collection charge increases as LET increases.展开更多
Despite advances in photocatalytic half-reduction reactions,challenges remain in effectively utilizing electron-hole pairs in concurrent redox processes.The present study involved the construction of a p-n junction Co...Despite advances in photocatalytic half-reduction reactions,challenges remain in effectively utilizing electron-hole pairs in concurrent redox processes.The present study involved the construction of a p-n junction Co_(3)O_(4)/Zn_(3)In_(2)S_(6)(CoZ)hybrid with a complementary band edge potential.The photocatalyst formed by the 2D assembled-nanostructure portrayed an optimal yield of 13.8(H_(2))and 13.1(benzaldehyde)mmol g^(-1)h^(-1)when exposed to light(λ>420 nm),surpassing 1%Pt-added ZIS(12.4(H_(2))and 10.71(benzaldehyde)mmol g^(-1)h^(-1)).Around 95%of the electron-hole utilization rate was achieved.The solar-to-hydrogen(STH)and apparent quantum yield(AQY)values of 0.466%and 4.96%(420nm)achieved by this system in the absence of sacrificial agents exceeded those of previous works.The exceptional performance was mostly ascribed to the synergistic development of adjoining p-n heterojunctions and the built-in electric field for effective charge separation.Moreover,scavenger studies elucidated the intricate mechanistic enigma of the dual-redox process,in which benzaldehyde was produced via O-H activation and subsequent C-H cleavage of benzyl alcohol over CoZ hybrids.Furthermore,the widespread use of the optimal 1-CoZ composites was confirmed in multiple photoredox systems.This work presents an innovative perspective on the construction of dual-functioning p-n heterojunctions for practical photoredox applications.展开更多
Thallium(Tl)compounds,highly toxic to biology,are usually released into flue gas during fossil/minerals combustion,and further distributed in water and soil.In this work,we fundamentally investigated the capture of ga...Thallium(Tl)compounds,highly toxic to biology,are usually released into flue gas during fossil/minerals combustion,and further distributed in water and soil.In this work,we fundamentally investigated the capture of gaseous Tl_(2)O by industrial V2O5-WO3/TiO_(2)catalyst under working condition in Tl-containing flue gas.Experimental and theoretical results indicated that the Tl_(2)O has significant electron-feeding capacity and easily donate electron to unoccupied orbitals of TiO_(2),leading to dismutation of Ti 2p and inartificial formation of p-n junction on TiO_(2)surface,which prompted Tl_(2)O selectively interacted with TiO_(2)in flue gas.Herein,we proposed and verified an effective way to capture gaseous Tl_(2)O,which offered almost the best choice to eliminate Tl emission from flue gas and expanded the function of the TiO_(2)-based catalyst.The formation of p-n junction on commercial V2O5-WO3/TiO_(2)catalyst under working condition was revealed for the first time,which can be a valuable reference for both heterocatalysis and electro/photocatalysis.展开更多
Absorption and carrier transport behavior plays an important role in the light-to-electricity conversion process,which is difficult to characterize.Here we develop a method to visualize such a conversion process in th...Absorption and carrier transport behavior plays an important role in the light-to-electricity conversion process,which is difficult to characterize.Here we develop a method to visualize such a conversion process in the InGaN/GaN multiquantum wells embedded in a p-n junction.Under non-resonant absorption conditions,a photocurrent was generated and the photoluminescence intensity decayed by more than 70%when the p-n junction out-circuit was switched from open to short.However,when the excitation photon energy decreased to the resonant absorption edge,the photocurrent dropped drastically and the photoluminescence under open and short circuit conditions showed similar intensity.These results indicate that the escaping of the photo-generated carriers from the quantum wells is closely related to the excitation photon energy.展开更多
Thin films of perovskite manganese oxide Lao.66Ca0.29K0.05MnO3（LCKMO） on Au/ITO（ITO=indium tin oxide） substrates were prepared by off-axis radio frequency magnetron sputtering and characterized by X-ray diffrac- t...Thin films of perovskite manganese oxide Lao.66Ca0.29K0.05MnO3（LCKMO） on Au/ITO（ITO=indium tin oxide） substrates were prepared by off-axis radio frequency magnetron sputtering and characterized by X-ray diffrac- tion（XRD）, high-resolution transmission electron microscopy（HRTEM）, and conductive atomic force microscopy （C-AFM） at room temperature. The thin films with thickness ranged from 100 nm to 300 nm basically show cubic structures with a=0.3886 nm, the same as that of the raw material used, but the structures are highly modulated. C-AFM results revealed that the atomic scale p-n junction feature of the thin films was the same as that of the single crystals. The preparation of the thin films thus further confirms the possibility of their application extending from micrometer-sized single crystals to macroscopic thin film.展开更多
Effective spin-polarized injection from magnetic semiconductor （MS） to nonmagnetic semiconductor （NMS） has been highlighted in recent years. In this paper we study theoretically the dependence of nonequilibrium sp...Effective spin-polarized injection from magnetic semiconductor （MS） to nonmagnetic semiconductor （NMS） has been highlighted in recent years. In this paper we study theoretically the dependence of nonequilibrium spin polarization （NESP） in NMS during spin-polarized injection through the magnetic p-n junction. Based on the theory in semiconductor physics, a model is established and the boundary conditions are determined in the case of no external spin-polarized injection and low bias. The control parameters that may influence the NESP in NMS are indicated by calculating the distribution of spin polarization. They are the doping concentrations, the equilibrium spin polarization in MS and the bias. The effective spin-polarized injection can be realized more easily by optimizing the above parameters.展开更多
Porous materials used for humidity sensing have been commercialized.In this paper,the preparation and humidity sensing characteristics of porous silicon with P-N junctions (PNJPS)are studied.PNJPS is made by electro-c...Porous materials used for humidity sensing have been commercialized.In this paper,the preparation and humidity sensing characteristics of porous silicon with P-N junctions (PNJPS)are studied.PNJPS is made by electro-chemical anodic etched method from silicon wafers with P-N junctions.Its porous structure is verified by scanning electronic micrograph. Experiments also show that PNJPS has high sensitivity,short response time (less than 30 seconds),and long-term stability.展开更多
Through theoretical analyses of the Shockley equation and the difference between a practical P-N junction and its ideal model, the mathematical models of P-N junction and solar cells had been obtained. With Matlab sof...Through theoretical analyses of the Shockley equation and the difference between a practical P-N junction and its ideal model, the mathematical models of P-N junction and solar cells had been obtained. With Matlab software, the V-I characteristics of diodes and solar cells were simulated, and a computer simulation model of the solar cells based on P-N junction was also established. Based on the simulation model, the influences of solar cell’s internal resistances on open-circuit voltage and short-circuit current under certain illumination were numerically analyzed and solved. The simulation results showed that the equivalent series resistance and shunt resistance could strongly affect the V-I characteristics of solar cell, but their influence styles were different.展开更多
The state of the p-n junction is very important to explain the performances of a solar cell. Some works give the influence of the electric field on the junction capacitance. However, these works do not relate the qual...The state of the p-n junction is very important to explain the performances of a solar cell. Some works give the influence of the electric field on the junction capacitance. However, these works do not relate the quality of the p-n junction under the electic field. The present manuscript is about a theoretical modelling of the p-n junction capacitance behavior of the polycrystalline silicon solar cell under an integration of the external electrical field source. An external electrical source is integrated in a solar cell system. The electronic carriers charge generated in the solar cell crossed mainly the junction with the great strength external electrical field. In open circuit, this crossing of the electronic charge carriers causes the thermal heating of the p-n junction by Joule effect. The p-n junction capacitance plotted versus the junction dynamic velocity and the photo-voltage for different external electrical fields. The electric field causes the decrease of the photo-voltage mainly the open-circuit photo-voltage. The decrease of the photo-voltage translates the narrowing of the Space Charge Region (SCR). The average value of the external electric field used in this study is not sufficient to cause the breakdown of the p-n junction of the solar cell system under integration of the external electrical field production source. The increase of the electrical field causes rather the narrowing of the SCR. That can provide an improvement of the solar cell’s electrical outputs.展开更多
The sluggish kinetics of the oxygen reduction reaction(ORR)and high over potential of oxygen evolution reaction(OER)are big challenges in the development of high-performance zinc-air batteries(ZABs)and fuel cells.In t...The sluggish kinetics of the oxygen reduction reaction(ORR)and high over potential of oxygen evolution reaction(OER)are big challenges in the development of high-performance zinc-air batteries(ZABs)and fuel cells.In this work,we report a rational design and a simple fabrication strategy of a photo-enhanced Co single-atom catalyst(SAC)comprising g-C3N4 coupled with cobalt-nitrogen-doped hierarchical mesoporous carbon(Co-N/MPC),forming a staggered p-n heterojunction that effectively improves charge separation and enhances electrocatalytic activity.The incorporation of Co SACs and g-C3N4 synergistically optimizes the photogenerated electron-hole pair separation,significantly boosting the intrinsic ORR-OER duplex activity.Under illumination,g-C_(3)N_(4)@Co-N/MPC exhibits an outstanding ORR half-wave potential(E1/2)of 0.841 V(vs.RHE)in 0.1 mol L^(–1)KOH and a low OER overpotential of 497.4 mV(vs.RHE)at 10 mA cm^(–2)in 1 mol L^(–1)KOH.Notably,the catalyst achieves an exceptional peak power density of 850.7 mW cm^(–2)in ZABs and of 411 mW cm^(–2)even in H_(2)-air fuel cell.In addition,g-C_(3)N_(4)@Co-N/MPC-based ZABs also show remarkable cycling stability exceeding 250 h.The advanced photo-induced charge separation at the p-n heterojunction facilitates faster electron transfer kinetics,and the mass transport owing to hierarchical mesoporous structure of Co-N-C,thereby reducing the overpotential and enhancing the overall energy conversion efficiency.This work provides a new perspective on designing next-generation of single-atom dispersed oxygen reaction catalysts,paving the way for high-performance photo-enhanced energy storage and conversion systems.展开更多
Mitochondrial dysfunction and oxidative stress are widely regarded as primary drivers of aging and are associated with several neurodegenerative diseases.The degeneration of motor neurons during aging is a critical pa...Mitochondrial dysfunction and oxidative stress are widely regarded as primary drivers of aging and are associated with several neurodegenerative diseases.The degeneration of motor neurons during aging is a critical pathological factor contributing to the progression of sarcopenia.However,the morphological and functional changes in mitochondria and their interplay in the degeneration of the neuromuscular junction during aging remain poorly understood.A defined systematic search of the Pub Med,Web of Science and Embase databases(last accessed on October 30,2024)was conducted with search terms including'mitochondria','aging'and'NMJ'.Clinical and preclinical studies of mitochondrial dysfunction and neuromuscular junction degeneration during aging.Twentyseven studies were included in this systematic review.This systematic review provides a summary of morphological,functional and biological changes in neuromuscular junction,mitochondrial morphology,biosynthesis,respiratory chain function,and mitophagy during aging.We focus on the interactions and mechanisms underlying the relationship between mitochondria and neuromuscular junctions during aging.Aging is characterized by significant reductions in mitochondrial fusion/fission cycles,biosynthesis,and mitochondrial quality control,which may lead to neuromuscular junction dysfunction,denervation and poor physical performance.Motor nerve terminals that exhibit redox sensitivity are among the first to exhibit abnormalities,ultimately leading to an early decline in muscle strength through impaired neuromuscular junction transmission function.Parg coactivator 1 alpha is a crucial molecule that regulates mitochondrial biogenesis and modulates various pathways,including the mitochondrial respiratory chain,energy deficiency,oxidative stress,and inflammation.Mitochondrial dysfunction is correlated with neuromuscular junction denervation and acetylcholine receptor fragmentation,resulting in muscle atrophy and a decrease in strength during aging.Physical therapy,pharmacotherapy,and gene therapy can alleviate the structural degeneration and functional deterioration of neuromuscular junction by restoring mitochondrial function.Therefore,mitochondria are considered potential targets for preserving neuromuscular junction morphology and function during aging to treat sarcopenia.展开更多
Gastric cancer(GC)is the fifth most prevalent malignancy worldwide and remains a leading cause of cancer-related mortality.Major risk factors for GC include Helicobacter pylori infection,increasing age,high dietary sa...Gastric cancer(GC)is the fifth most prevalent malignancy worldwide and remains a leading cause of cancer-related mortality.Major risk factors for GC include Helicobacter pylori infection,increasing age,high dietary salt intake,and diets deficient in vegetables and fruits.Due to the often subtle and nonspecific early symptoms,coupled with the lack of routine screening programs,a significant proportion of GC cases are diagnosed at advanced stages.The etiology of GC is multifactorial,and diagnosis is confirmed histologically through endoscopic biopsy,followed by staging via computed tomography,positron emission tomography,staging laparoscopy,and endoscopic ultrasound.Treatment strategies typically involve a multidisciplinary approach including chemotherapy,surgical resection,radiotherapy,and emerging immunotherapeutic options.Despite advances in diagnostic and therapeutic modalities,the prognosis of advanced GC remains poor,with high rates of recurrence and metastasis.In recent years,increasing attention has been given to the role of tight junction(TJ)proteins in the pathogenesis and progression of GC.TJ proteins,critical components of epithelial barrier function,have been implicated in various stages of gastric carcinogenesis,from intestinal metaplasia to invasion and metastasis.Infection and inflammation,particularly due to Helicobacter pylori,disrupt TJ integrity,compromising the gastric mucosal barrier and facilitating neoplastic transformation.This review synthesizes current evidence from PubMed,EMBASE,Google Scholar,ScienceDirect,SpringerLink,and other reputable databases to provide a comprehensive overview of the involvement of TJ proteins in GC.By elucidating the molecular interplay between TJ dysregulation and gastric tumorigenesis,this work aims to highlight the potential of TJ proteins as novel diagnostic biomarkers and therapeutic targets in GC management.展开更多
Two-dimensional （2D） materials have attracted substantial attention in electronic and optoelectronic applications with the superior advantages of being flexible, transparent, and highly tunable. Gapless graphene exh...Two-dimensional （2D） materials have attracted substantial attention in electronic and optoelectronic applications with the superior advantages of being flexible, transparent, and highly tunable. Gapless graphene exhibits ultra-broadband and fast photoresponse while the 2D semiconducting MoS2 and GaTe exhibit high sensitivity and tunable responsivity to visible light. However, the device yield and repeatability call for further improvement to achieve large-scale uniformity. Here, we report a layer-by-layer growth of wafer-scale GaTe with a high hole mobility of 28.4 cm^2/（V.s） by molecular beam epitaxy. The arrayed p-n ）unctions were developed by growing few-layer GaTe directly on fhree-inch Si wafers. The resultant diodes reveal good rectifying characteristics and a high photovoltaic external quantum efficiency up to 62% at 4.8 μW under zero bias. The photocurrent reaches saturation fast enough to capture a time constant of 22 μs and shows no sign of device degradation after 1.37 million cycles of operation. Most strikingly, such high performance has been achieved across the entire wafer, making the volume production of devices accessible. Finally, several photoimages were acquired by the GaTe/Si photodiodes with reasonable contrast and spatial resolution, demonstrating the potential of integrating the 2D materials with silicon technology for novel optoelectronic devices.展开更多
The emulation of biological synapses with learning and memory functions and versatile plasticity is significantly promising for neuromorphic computing systems.Here,a robust and continuously adjustable mechanoplastic s...The emulation of biological synapses with learning and memory functions and versatile plasticity is significantly promising for neuromorphic computing systems.Here,a robust and continuously adjustable mechanoplastic semifloating-gate transistor is demonstrated based on an integrated graphene/hexagonal boron nitride/tungsten diselenide van der Waals heterostructure and a triboelectric nanogenerator(TENG).The working states(p-n junction or n;-n junction)can be manipulated and switched under the sophisticated modulation of triboelectric potential derived from mechanical actions,which is attributed to carriers trapping and detrapping in the graphene layer.Furthermore,a reconfigurable artificial synapse is constructed based on such mechanoplastic transistor that can simulate typical synaptic plasticity and implement dynamic control correlations in each response mode by further designing the amplitude and duration.The artificial synapse can work with ultra-low energy consumption at 74.2 f J per synaptic event and the extended synaptic weights.Under the synergetic effect of the semifloating gate,the synaptic device can enable successive mechanical facilitation/depression,short-/long-term plasticity and learning-experience behavior,exhibiting the mechanical behavior derived synaptic plasticity.Such reconfigurable and mechanoplastic features provide an insight into the applications of energyefficient and real-time interactive neuromodulation in the future artificial intelligent system beyond von Neumann architecture.展开更多
Neuromorphic machine vision has attracted extensive attention on wide fields.However,both current and emerging strategies still suffer from power/time inefficiency,and/or low compatibility,complex device structure.Her...Neuromorphic machine vision has attracted extensive attention on wide fields.However,both current and emerging strategies still suffer from power/time inefficiency,and/or low compatibility,complex device structure.Here we demonstrate a driving-voltage-free optoelectronic synaptic device using non-volatile reconfigurable photovoltaic effect based on MoTe_(2)/α-In_(2)Se_(3) ferroelectric p-n junctions.This function comes from the non-volatile reconfigurable built-in potential in the p-n junction that is related to the ferroelectric polarization inα-In_(2)Se_(3).Reconfigurable rectification behavior and photovoltaic effect are demonstrated firstly.Notably,the figure-of-merits for photovoltaic effect like photoelectrical conversion efficiency non-volatilely increases more than one order.Based on this,retina synapse-like vision functions are mimicked.Optoelectronic short-term and long-term plasticity,as well as basic neuromorphic learning and memory rule are achieved without applying driving voltage.Our work highlights the potential of ferroelectric p-n junctions for enhanced solar cell and low-power optoelectronic synaptic device for neuromorphic machine vision.展开更多
Microcystin-RR（MC-RR）,a form of microcystin with two arginine moieties,is a cyanobacterial toxin that has been detected across a wide geographic range.It is a great concern globally because of its potential liver to...Microcystin-RR（MC-RR）,a form of microcystin with two arginine moieties,is a cyanobacterial toxin that has been detected across a wide geographic range.It is a great concern globally because of its potential liver toxicity.Herein,the abilities of BiVO4,Ag-BiVO4,Ag2O-BiVO4 and Ag/Ag2O-BiVO4 to photocatalytically degrade MC-RR under visible-light irradiation（λ≥420 nm） were investigated and compared.The possible degradation pathways were explored through analysis of the reaction intermediates by high-performance liquid chromatography-mass spectrometry.The results showed that the presence of Ag^0 enhanced the photocatalytic efficiency of Ag/Ag2O-BiVO4 via a synergetic effect between Ag2O and Ag^0 at the p-n heterojunction.Moreover,the presence of Ag^0 also greatly promoted the adsorption of MC-RR on the photocatalyst surface.Toxicological experiments on mice showed that the toxicity of MC-RR was significantly reduced after photocatalytic degradation.展开更多
The rational design of robust photoactive material and artful sensing strategy are vital for the construction of an ultrasensitive photoelectrochemical（PEC） sensor. Although great progress has been made in PEC sensi...The rational design of robust photoactive material and artful sensing strategy are vital for the construction of an ultrasensitive photoelectrochemical（PEC） sensor. Although great progress has been made in PEC sensing, the resultant detection performances and adoptable sensing strategies are still limited. Herein, through the design of a subtle component reconstitution strategy, an ultrasensitive PEC sensor is developed for the detection of Cu2+ based on advanced Cu S/Cd S nanohybrids（NHs）.This proposed sensor shows superior sensing performances with a low detection limit of 0.1 n M and a wide detection range from0.2 n M to 60 μM due to the formation of p-n junction between Cu S and Cd S and the component transformation of Cd S to CuxS（x=1,2）. Moreover, such PEC sensor also displays goodish results for monitoring the Cu2+released from apoptotic He La cells in vitro. This idea of component reconstitution provides a new paradigm for the design of advanced PEC sensors.展开更多
基金The Natural Science Foundation of Guangdong Province(Project No.2023A1515012352)。
文摘Zinc oxide(ZnO),as a broadband gap semiconductor material,exhibits unique physical and chemical properties that make it highly suitable for optoelectronics,piezoelectric devices,and gas-sensitive sensors,showing significant potential for various applications.This paper focuses on the regulation and application of ZnO-based p-n junctions and piezoelectric devices.It discusses in detail the preparation of ZnO materials,the construction of p-n junctions,the optimization of piezoelectric device performance,and its application in various fields.By employing different preparation methods and strategies,high-quality ZnO thin films can be grown,and effective control of p-type conductivity achieved.This study provides both a theoretical foundation and technical support for controlling the performance of ZnO-based piezoelectric devices,as well as paving new pathways for the broader application of ZnO materials.
基金supported by the National Key R&D Program of China(Grant Nos.2022YFB3605500 and 2022YFB3605503).
文摘The p-n junction is the foundation building structure for manufacturing various electronic and optoelec-tronic devices.Ultrawide bandgap semiconductors are expected to overcome the limited power capability of Si-based electronic device,however,it is very difficult to achieve efficient bipolar doping due to the asymmetric doping effect,thereby impeding the development of p-n homojunction and related bipolar devices,especially for the Ga_(2)O_(3)-based materials and devices.Here,we demonstrate a unique one-step integrated growth of p-type N-doped(201)β-Ga_(2)O_(3)/n-type Si-doped(¯201)β-Ga_(2)O_(3)films by phase tran-sition and in-situ pre-doping of dopants,and fabrication of fullβ-Ga_(2)O_(3)linearly-graded p-n homojunc-tion diode from them.The fullβ-Ga_(2)O_(3)p-n homojunction diode possesses a large built-in potential of 4.52 eV,a high operation electric field>2.90 MV/cm in the reverse-bias regime,good longtime-stable rectifying behaviors with a rectification ratio of 104,and a high-speed switching and good surge robust-ness with a weak minority-carrier charge storage.Our work opens the way to the fabrication of Ga_(2)O_(3)-based p-n homojunction,lays the foundation for fullβ-Ga_(2)O_(3)-based bipolar devices,and paves the way for the novel fabrication of p-n homojunction for wide-bandgap oxides.
文摘Polycrystalline diamond thin films are deposited on an n-type Si substrates by hot filament chemical vapor deposition,and then are implanted with boron ions in a 200keV ion implanter.In order to achieve a better distribution of the implanted element,boron ions are implanted by two steps:implanting boron ions with the energy of 70keV first,and then with the energy of 100keV.The homogeneous distribution of the B ion is gained.The current-voltage characteristics of the samples are studied.It is found that the p-n heterojunction effect is achieved in these samples.
文摘Single event transient of a real p-n junction in a 0.18μm bulk process is studied by 3D TCAD simulation. The impact of voltage, temperature, substrate concentration, and LET on SET is studied. Our simulation results demonstrate that biases in the range 1.62 to 1.98V influence DSET current shape greatly and total collected charge weakly. Peak current and charge collection within 2ns decreases as temperature increases,and temperature has a stronger influence on SET currents than on total charge. Typical variation of substrate concentration in modern VDSM processes has a negligible effect on SEEs. Both peak current and total collection charge increases as LET increases.
基金support provided by the Ministry of Higher Education Malaysia under the Fundamental Research Grant Scheme(FRGS)(No.FRGS/1/2024/TK08/XMU/02/1)supported by the PETRONAS-Academia Collaboration Dialogue(PACD 2023)grant,provided by PETRONAS Research Sdn.Bhd.(PRSB)+6 种基金the Ministry of Science,Technology and Innovation(MOSTI)Malaysia under the Strategic Research Fund(SRF)(S.22015)supported by the National Natural Science Foundation of China(No.22202168)Guangdong Basic and Applied Basic Research Foundation(No.2021A1515111019)support from the State Key Laboratory of Physical Chemistry of Solid Surfaces,Xiamen University(No.2023X11)supported by the Embassy of the People's Republic of China in Malaysia(EENG/0045)funded by Xiamen University Malaysia Investigatorship Grant(No.IENG/0038)Xiamen University Malaysia Research Fund(ICOE/0001,XMUMRF/2021-C8/IENG/0041 and XMUMRF/2025-C15/IENG/0080).
文摘Despite advances in photocatalytic half-reduction reactions,challenges remain in effectively utilizing electron-hole pairs in concurrent redox processes.The present study involved the construction of a p-n junction Co_(3)O_(4)/Zn_(3)In_(2)S_(6)(CoZ)hybrid with a complementary band edge potential.The photocatalyst formed by the 2D assembled-nanostructure portrayed an optimal yield of 13.8(H_(2))and 13.1(benzaldehyde)mmol g^(-1)h^(-1)when exposed to light(λ>420 nm),surpassing 1%Pt-added ZIS(12.4(H_(2))and 10.71(benzaldehyde)mmol g^(-1)h^(-1)).Around 95%of the electron-hole utilization rate was achieved.The solar-to-hydrogen(STH)and apparent quantum yield(AQY)values of 0.466%and 4.96%(420nm)achieved by this system in the absence of sacrificial agents exceeded those of previous works.The exceptional performance was mostly ascribed to the synergistic development of adjoining p-n heterojunctions and the built-in electric field for effective charge separation.Moreover,scavenger studies elucidated the intricate mechanistic enigma of the dual-redox process,in which benzaldehyde was produced via O-H activation and subsequent C-H cleavage of benzyl alcohol over CoZ hybrids.Furthermore,the widespread use of the optimal 1-CoZ composites was confirmed in multiple photoredox systems.This work presents an innovative perspective on the construction of dual-functioning p-n heterojunctions for practical photoredox applications.
基金financially supported by the National Natural Science Foundation of China(21936005,52070114 and 21876093)Tsinghua-Foshan Innovation Special Fund(TFISF).
文摘Thallium(Tl)compounds,highly toxic to biology,are usually released into flue gas during fossil/minerals combustion,and further distributed in water and soil.In this work,we fundamentally investigated the capture of gaseous Tl_(2)O by industrial V2O5-WO3/TiO_(2)catalyst under working condition in Tl-containing flue gas.Experimental and theoretical results indicated that the Tl_(2)O has significant electron-feeding capacity and easily donate electron to unoccupied orbitals of TiO_(2),leading to dismutation of Ti 2p and inartificial formation of p-n junction on TiO_(2)surface,which prompted Tl_(2)O selectively interacted with TiO_(2)in flue gas.Herein,we proposed and verified an effective way to capture gaseous Tl_(2)O,which offered almost the best choice to eliminate Tl emission from flue gas and expanded the function of the TiO_(2)-based catalyst.The formation of p-n junction on commercial V2O5-WO3/TiO_(2)catalyst under working condition was revealed for the first time,which can be a valuable reference for both heterocatalysis and electro/photocatalysis.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2016YFB0400302 and 2016YFB0400603)the National Natural Science Foundation of China(Grant Nos.11574362,61210014,and 11374340)the Innovative Clean-Energy Research and Application Program of Beijing Municipal Science and Technology Commission,China(Grant No.Z151100003515001)
文摘Absorption and carrier transport behavior plays an important role in the light-to-electricity conversion process,which is difficult to characterize.Here we develop a method to visualize such a conversion process in the InGaN/GaN multiquantum wells embedded in a p-n junction.Under non-resonant absorption conditions,a photocurrent was generated and the photoluminescence intensity decayed by more than 70%when the p-n junction out-circuit was switched from open to short.However,when the excitation photon energy decreased to the resonant absorption edge,the photocurrent dropped drastically and the photoluminescence under open and short circuit conditions showed similar intensity.These results indicate that the escaping of the photo-generated carriers from the quantum wells is closely related to the excitation photon energy.
基金Supported by the National Natural Science Foundation of China(No.90922034)
文摘Thin films of perovskite manganese oxide Lao.66Ca0.29K0.05MnO3（LCKMO） on Au/ITO（ITO=indium tin oxide） substrates were prepared by off-axis radio frequency magnetron sputtering and characterized by X-ray diffrac- tion（XRD）, high-resolution transmission electron microscopy（HRTEM）, and conductive atomic force microscopy （C-AFM） at room temperature. The thin films with thickness ranged from 100 nm to 300 nm basically show cubic structures with a=0.3886 nm, the same as that of the raw material used, but the structures are highly modulated. C-AFM results revealed that the atomic scale p-n junction feature of the thin films was the same as that of the single crystals. The preparation of the thin films thus further confirms the possibility of their application extending from micrometer-sized single crystals to macroscopic thin film.
基金Project supported by the National Natural Science Foundation of China （Grant No 60606021）, the Specialized Research Fund for the Doctoral Program of Higher Education of China （Grant No 20060003067） and the Key Fundamental Research Foundation of Tsinghua University of China （Grant No Jz2001010）.
文摘Effective spin-polarized injection from magnetic semiconductor （MS） to nonmagnetic semiconductor （NMS） has been highlighted in recent years. In this paper we study theoretically the dependence of nonequilibrium spin polarization （NESP） in NMS during spin-polarized injection through the magnetic p-n junction. Based on the theory in semiconductor physics, a model is established and the boundary conditions are determined in the case of no external spin-polarized injection and low bias. The control parameters that may influence the NESP in NMS are indicated by calculating the distribution of spin polarization. They are the doping concentrations, the equilibrium spin polarization in MS and the bias. The effective spin-polarized injection can be realized more easily by optimizing the above parameters.
基金National Natural This work was supported Science Foundation of P. R by the China （Grant number： 69666001）West Glory project of Chinese Academy of Science.
文摘Porous materials used for humidity sensing have been commercialized.In this paper,the preparation and humidity sensing characteristics of porous silicon with P-N junctions (PNJPS)are studied.PNJPS is made by electro-chemical anodic etched method from silicon wafers with P-N junctions.Its porous structure is verified by scanning electronic micrograph. Experiments also show that PNJPS has high sensitivity,short response time (less than 30 seconds),and long-term stability.
文摘Through theoretical analyses of the Shockley equation and the difference between a practical P-N junction and its ideal model, the mathematical models of P-N junction and solar cells had been obtained. With Matlab software, the V-I characteristics of diodes and solar cells were simulated, and a computer simulation model of the solar cells based on P-N junction was also established. Based on the simulation model, the influences of solar cell’s internal resistances on open-circuit voltage and short-circuit current under certain illumination were numerically analyzed and solved. The simulation results showed that the equivalent series resistance and shunt resistance could strongly affect the V-I characteristics of solar cell, but their influence styles were different.
文摘The state of the p-n junction is very important to explain the performances of a solar cell. Some works give the influence of the electric field on the junction capacitance. However, these works do not relate the quality of the p-n junction under the electic field. The present manuscript is about a theoretical modelling of the p-n junction capacitance behavior of the polycrystalline silicon solar cell under an integration of the external electrical field source. An external electrical source is integrated in a solar cell system. The electronic carriers charge generated in the solar cell crossed mainly the junction with the great strength external electrical field. In open circuit, this crossing of the electronic charge carriers causes the thermal heating of the p-n junction by Joule effect. The p-n junction capacitance plotted versus the junction dynamic velocity and the photo-voltage for different external electrical fields. The electric field causes the decrease of the photo-voltage mainly the open-circuit photo-voltage. The decrease of the photo-voltage translates the narrowing of the Space Charge Region (SCR). The average value of the external electric field used in this study is not sufficient to cause the breakdown of the p-n junction of the solar cell system under integration of the external electrical field production source. The increase of the electrical field causes rather the narrowing of the SCR. That can provide an improvement of the solar cell’s electrical outputs.
文摘The sluggish kinetics of the oxygen reduction reaction(ORR)and high over potential of oxygen evolution reaction(OER)are big challenges in the development of high-performance zinc-air batteries(ZABs)and fuel cells.In this work,we report a rational design and a simple fabrication strategy of a photo-enhanced Co single-atom catalyst(SAC)comprising g-C3N4 coupled with cobalt-nitrogen-doped hierarchical mesoporous carbon(Co-N/MPC),forming a staggered p-n heterojunction that effectively improves charge separation and enhances electrocatalytic activity.The incorporation of Co SACs and g-C3N4 synergistically optimizes the photogenerated electron-hole pair separation,significantly boosting the intrinsic ORR-OER duplex activity.Under illumination,g-C_(3)N_(4)@Co-N/MPC exhibits an outstanding ORR half-wave potential(E1/2)of 0.841 V(vs.RHE)in 0.1 mol L^(–1)KOH and a low OER overpotential of 497.4 mV(vs.RHE)at 10 mA cm^(–2)in 1 mol L^(–1)KOH.Notably,the catalyst achieves an exceptional peak power density of 850.7 mW cm^(–2)in ZABs and of 411 mW cm^(–2)even in H_(2)-air fuel cell.In addition,g-C_(3)N_(4)@Co-N/MPC-based ZABs also show remarkable cycling stability exceeding 250 h.The advanced photo-induced charge separation at the p-n heterojunction facilitates faster electron transfer kinetics,and the mass transport owing to hierarchical mesoporous structure of Co-N-C,thereby reducing the overpotential and enhancing the overall energy conversion efficiency.This work provides a new perspective on designing next-generation of single-atom dispersed oxygen reaction catalysts,paving the way for high-performance photo-enhanced energy storage and conversion systems.
基金supported by grants from Collaborative Research Fund(Ref:C4032-21GF)General Research Grant(Ref:14114822)+1 种基金Group Research Scheme(Ref:3110146)Area of Excellence(Ref:Ao E/M-402/20)。
文摘Mitochondrial dysfunction and oxidative stress are widely regarded as primary drivers of aging and are associated with several neurodegenerative diseases.The degeneration of motor neurons during aging is a critical pathological factor contributing to the progression of sarcopenia.However,the morphological and functional changes in mitochondria and their interplay in the degeneration of the neuromuscular junction during aging remain poorly understood.A defined systematic search of the Pub Med,Web of Science and Embase databases(last accessed on October 30,2024)was conducted with search terms including'mitochondria','aging'and'NMJ'.Clinical and preclinical studies of mitochondrial dysfunction and neuromuscular junction degeneration during aging.Twentyseven studies were included in this systematic review.This systematic review provides a summary of morphological,functional and biological changes in neuromuscular junction,mitochondrial morphology,biosynthesis,respiratory chain function,and mitophagy during aging.We focus on the interactions and mechanisms underlying the relationship between mitochondria and neuromuscular junctions during aging.Aging is characterized by significant reductions in mitochondrial fusion/fission cycles,biosynthesis,and mitochondrial quality control,which may lead to neuromuscular junction dysfunction,denervation and poor physical performance.Motor nerve terminals that exhibit redox sensitivity are among the first to exhibit abnormalities,ultimately leading to an early decline in muscle strength through impaired neuromuscular junction transmission function.Parg coactivator 1 alpha is a crucial molecule that regulates mitochondrial biogenesis and modulates various pathways,including the mitochondrial respiratory chain,energy deficiency,oxidative stress,and inflammation.Mitochondrial dysfunction is correlated with neuromuscular junction denervation and acetylcholine receptor fragmentation,resulting in muscle atrophy and a decrease in strength during aging.Physical therapy,pharmacotherapy,and gene therapy can alleviate the structural degeneration and functional deterioration of neuromuscular junction by restoring mitochondrial function.Therefore,mitochondria are considered potential targets for preserving neuromuscular junction morphology and function during aging to treat sarcopenia.
文摘Gastric cancer(GC)is the fifth most prevalent malignancy worldwide and remains a leading cause of cancer-related mortality.Major risk factors for GC include Helicobacter pylori infection,increasing age,high dietary salt intake,and diets deficient in vegetables and fruits.Due to the often subtle and nonspecific early symptoms,coupled with the lack of routine screening programs,a significant proportion of GC cases are diagnosed at advanced stages.The etiology of GC is multifactorial,and diagnosis is confirmed histologically through endoscopic biopsy,followed by staging via computed tomography,positron emission tomography,staging laparoscopy,and endoscopic ultrasound.Treatment strategies typically involve a multidisciplinary approach including chemotherapy,surgical resection,radiotherapy,and emerging immunotherapeutic options.Despite advances in diagnostic and therapeutic modalities,the prognosis of advanced GC remains poor,with high rates of recurrence and metastasis.In recent years,increasing attention has been given to the role of tight junction(TJ)proteins in the pathogenesis and progression of GC.TJ proteins,critical components of epithelial barrier function,have been implicated in various stages of gastric carcinogenesis,from intestinal metaplasia to invasion and metastasis.Infection and inflammation,particularly due to Helicobacter pylori,disrupt TJ integrity,compromising the gastric mucosal barrier and facilitating neoplastic transformation.This review synthesizes current evidence from PubMed,EMBASE,Google Scholar,ScienceDirect,SpringerLink,and other reputable databases to provide a comprehensive overview of the involvement of TJ proteins in GC.By elucidating the molecular interplay between TJ dysregulation and gastric tumorigenesis,this work aims to highlight the potential of TJ proteins as novel diagnostic biomarkers and therapeutic targets in GC management.
基金This work was supported by the National Young 1000 Talent Plan, Pujiang Talent Plan in Shanghai, National Natural Science Foundation of China （Nos. 61322407, 11474058, and 11322441）, the Chinese Na- tional Science Fund for Talent Training in Basic Science （No. J1103204）, and Ten Thousand Talents Program for young talents. Part of the sample fabrication was performed at Fudan Nano-fabrication Laboratory. We acknowledge Yuanbo Zhang, Yizheng Wu, Zuimin Jiang, Likai Li, Boliang Chen for great assistance during the device fabrication and measurements.
文摘Two-dimensional （2D） materials have attracted substantial attention in electronic and optoelectronic applications with the superior advantages of being flexible, transparent, and highly tunable. Gapless graphene exhibits ultra-broadband and fast photoresponse while the 2D semiconducting MoS2 and GaTe exhibit high sensitivity and tunable responsivity to visible light. However, the device yield and repeatability call for further improvement to achieve large-scale uniformity. Here, we report a layer-by-layer growth of wafer-scale GaTe with a high hole mobility of 28.4 cm^2/（V.s） by molecular beam epitaxy. The arrayed p-n ）unctions were developed by growing few-layer GaTe directly on fhree-inch Si wafers. The resultant diodes reveal good rectifying characteristics and a high photovoltaic external quantum efficiency up to 62% at 4.8 μW under zero bias. The photocurrent reaches saturation fast enough to capture a time constant of 22 μs and shows no sign of device degradation after 1.37 million cycles of operation. Most strikingly, such high performance has been achieved across the entire wafer, making the volume production of devices accessible. Finally, several photoimages were acquired by the GaTe/Si photodiodes with reasonable contrast and spatial resolution, demonstrating the potential of integrating the 2D materials with silicon technology for novel optoelectronic devices.
基金supported by the National Natural Science Foundation of China(51872031,52073032,and 61904013)the Fundamental Research Funds for the Central Universities。
文摘The emulation of biological synapses with learning and memory functions and versatile plasticity is significantly promising for neuromorphic computing systems.Here,a robust and continuously adjustable mechanoplastic semifloating-gate transistor is demonstrated based on an integrated graphene/hexagonal boron nitride/tungsten diselenide van der Waals heterostructure and a triboelectric nanogenerator(TENG).The working states(p-n junction or n;-n junction)can be manipulated and switched under the sophisticated modulation of triboelectric potential derived from mechanical actions,which is attributed to carriers trapping and detrapping in the graphene layer.Furthermore,a reconfigurable artificial synapse is constructed based on such mechanoplastic transistor that can simulate typical synaptic plasticity and implement dynamic control correlations in each response mode by further designing the amplitude and duration.The artificial synapse can work with ultra-low energy consumption at 74.2 f J per synaptic event and the extended synaptic weights.Under the synergetic effect of the semifloating gate,the synaptic device can enable successive mechanical facilitation/depression,short-/long-term plasticity and learning-experience behavior,exhibiting the mechanical behavior derived synaptic plasticity.Such reconfigurable and mechanoplastic features provide an insight into the applications of energyefficient and real-time interactive neuromodulation in the future artificial intelligent system beyond von Neumann architecture.
基金This work was supported by the National Key R&D Program of China(Nos.2018YFA0703700 and 2016YFA0200700)the National Natural Science Foundation of China(Nos.91964203,61625401,61851403,61974036,61804146,and 61804035)+1 种基金the strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB30000000)CAS Key Laboratory of Nanosystem and Hierarchical Fabrication.The authors also gratefully acknowledge the support of Youth Innovation Promotion Association CAS.
文摘Neuromorphic machine vision has attracted extensive attention on wide fields.However,both current and emerging strategies still suffer from power/time inefficiency,and/or low compatibility,complex device structure.Here we demonstrate a driving-voltage-free optoelectronic synaptic device using non-volatile reconfigurable photovoltaic effect based on MoTe_(2)/α-In_(2)Se_(3) ferroelectric p-n junctions.This function comes from the non-volatile reconfigurable built-in potential in the p-n junction that is related to the ferroelectric polarization inα-In_(2)Se_(3).Reconfigurable rectification behavior and photovoltaic effect are demonstrated firstly.Notably,the figure-of-merits for photovoltaic effect like photoelectrical conversion efficiency non-volatilely increases more than one order.Based on this,retina synapse-like vision functions are mimicked.Optoelectronic short-term and long-term plasticity,as well as basic neuromorphic learning and memory rule are achieved without applying driving voltage.Our work highlights the potential of ferroelectric p-n junctions for enhanced solar cell and low-power optoelectronic synaptic device for neuromorphic machine vision.
基金supported by the National Natural Science Foundation of China (21677086, 21407092, 21377067, 21577078)the Natural Science Foundation for Innovation Group of Hubei Province, China (2015CFA021)~~
文摘Microcystin-RR（MC-RR）,a form of microcystin with two arginine moieties,is a cyanobacterial toxin that has been detected across a wide geographic range.It is a great concern globally because of its potential liver toxicity.Herein,the abilities of BiVO4,Ag-BiVO4,Ag2O-BiVO4 and Ag/Ag2O-BiVO4 to photocatalytically degrade MC-RR under visible-light irradiation（λ≥420 nm） were investigated and compared.The possible degradation pathways were explored through analysis of the reaction intermediates by high-performance liquid chromatography-mass spectrometry.The results showed that the presence of Ag^0 enhanced the photocatalytic efficiency of Ag/Ag2O-BiVO4 via a synergetic effect between Ag2O and Ag^0 at the p-n heterojunction.Moreover,the presence of Ag^0 also greatly promoted the adsorption of MC-RR on the photocatalyst surface.Toxicological experiments on mice showed that the toxicity of MC-RR was significantly reduced after photocatalytic degradation.
基金supported by the National Natural Science Foundation of China (21625502)Priority Academic Program Development and Postgraduate Research & Practice Innovation Program of Jiangsu Province (KYCX18,1188)
文摘The rational design of robust photoactive material and artful sensing strategy are vital for the construction of an ultrasensitive photoelectrochemical（PEC） sensor. Although great progress has been made in PEC sensing, the resultant detection performances and adoptable sensing strategies are still limited. Herein, through the design of a subtle component reconstitution strategy, an ultrasensitive PEC sensor is developed for the detection of Cu2+ based on advanced Cu S/Cd S nanohybrids（NHs）.This proposed sensor shows superior sensing performances with a low detection limit of 0.1 n M and a wide detection range from0.2 n M to 60 μM due to the formation of p-n junction between Cu S and Cd S and the component transformation of Cd S to CuxS（x=1,2）. Moreover, such PEC sensor also displays goodish results for monitoring the Cu2+released from apoptotic He La cells in vitro. This idea of component reconstitution provides a new paradigm for the design of advanced PEC sensors.
