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Highly Active Interfacial Sites in SFT-SnO_(2) Heterojunction Electrolyte for Enhanced Fuel Cell Performance via Engineered Energy Bands:Envisioned Theoretically and Experimentally 被引量:1
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作者 Sajid Rauf Muhammad Bilal Hanif +8 位作者 Faiz Wali Zuhra Tayyab Bin Zhu Naveed Mushtaq Yatao Yang Kashif Khan Peter D.Lund Martin Motola Wei Xu 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第3期384-397,共14页
Extending the ionic conductivity is the pre-requisite of electrolytes in fuel cell technology for high-electrochemical performance.In this regard,the introduction of semiconductor-oxide materials and the approach of h... Extending the ionic conductivity is the pre-requisite of electrolytes in fuel cell technology for high-electrochemical performance.In this regard,the introduction of semiconductor-oxide materials and the approach of heterostructure formation by modulating energy bands to enhance ionic conduction acting as an electrolyte in fuel cell-device.Semiconductor(n-type;SnO_(2))plays a key role by introducing into p-type SrFe_(0.2)Ti_(0.8)O_(3-δ)(SFT)semiconductor perovskite materials to construct p-n heterojunction for high ionic conductivity.Therefore,two different composites of SFT and SnO_(2)are constructed by gluing p-and n-type SFT-SnO_(2),where the optimal composition of SFT-SnO_(2)(6∶4)heterostructure electrolyte-based fuel cell achieved excellent ionic conductivity 0.24 S cm^(-1)with power-output of 1004 mW cm^(-2)and high OCV 1.12 V at a low operational temperature of 500℃.The high power-output and significant ionic conductivity with durable operation of 54 h are accredited to SFT-SnO_(2)heterojunction formation including interfacial conduction assisted by a built-in electric field in fuel cell device.Moreover,the fuel conversion efficiency and considerable Faradaic efficiency reveal the compatibility of SFT-SnO_(2)heterostructure electrolyte and ruled-out short-circuiting issue.Further,the first principle calculation provides sufficient information on structure optimization and energy-band structure modulation of SFT-SnO_(2).This strategy will provide new insight into semiconductor-based fuel cell technology to design novel electrolytes. 展开更多
关键词 high ionic conductivity interfacial conduction modulated energy band structure p-n heterojunction SEMICONDUCTORS
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Reanalysis of energy band structure in the type-II quantum wells
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作者 李欣欣 邓震 +4 位作者 江洋 杜春花 贾海强 王文新 陈弘 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第6期75-78,共4页
Band structure analysis holds significant importance for understanding the optoelectronic characteristics of semiconductor structures and exploring their potential applications in practice. For quantum well structures... Band structure analysis holds significant importance for understanding the optoelectronic characteristics of semiconductor structures and exploring their potential applications in practice. For quantum well structures, the energy of carriers in the well splits into discrete energy levels due to the confinement of barriers in the growth direction. However, the discrete energy levels obtained at a fixed wave vector cannot accurately reflect the actual energy band structure. In this work, the band structure of the type-II quantum wells is reanalyzed. When the wave vectors of the entire Brillouin region(corresponding to the growth direction) are taken into account, the quantized energy levels of the carriers in the well are replaced by subbands with certain energy distributions. This new understanding of the energy bands of low-dimensional structures not only helps us to have a deeper cognition of the structure, but also may overturn many viewpoints in traditional band theories and serve as supplementary to the band theory of low-dimensional systems. 展开更多
关键词 energy band structure type-II quantum wells low-dimensional semiconductors
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Interface and energy band manipulation of Bi2O3-Bi2S3 electrode enabling advanced magnesium-ion storage
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作者 Qiang Tang Yingze Song +4 位作者 Xuan Cao Cheng Yang Dong Wang Tingting Qin Wei Zhang 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第9期3543-3552,共10页
Rechargeable magnesium-ion(Mg-ion)batteries have attracted wide attention for energy storage.However,magnesium anode is still limited by the irreversible Mg plating/stripping procedure.Herein,a well-designed binary Bi... Rechargeable magnesium-ion(Mg-ion)batteries have attracted wide attention for energy storage.However,magnesium anode is still limited by the irreversible Mg plating/stripping procedure.Herein,a well-designed binary Bi_(2)O_(3)-Bi_(2)S_(3)(BO-BS)heterostructure is fulfilled by virtue of the cooperative interface and energy band engineering targeted fast Mg-ion storage.The built-in electronic field resulting from the asymmetrical electron distribution at the interface of electron-rich S center at Bi_(2)S_(3) side and electron-poor O center at Bi_(2)O_(3) side effectively accelerates the electrochemical reaction kinetics in the Mg-ion battery system.Moreover,the as-designed heterogenous interface also benefits to maintaining the electrode integrity.With these advantages,the BO-BS electrode displays a remarkable capacity of 150.36 mAh g^(−1) at 0.67 A g^(-1) and a superior cycling stability.This investigation would offer novel insights into the rational design of functional heterogenous electrode materials targeted the fast reaction kinetics for energy storage systems. 展开更多
关键词 Magnesium-ion battery Bi2O3-Bi2S3 heterostructure Interface and energy band engineering Electrochemical reaction kinetics Electrode integrity
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Quantum confinement of carriers in the type-I quantum wells structure
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作者 Xinxin Li Zhen Deng +4 位作者 Yang Jiang Chunhua Du Haiqiang Jia Wenxin Wang Hong Chen 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第9期553-558,共6页
Quantum confinement is recognized to be an inherent property in low-dimensional structures.Traditionally,it is believed that the carriers trapped within the well cannot escape due to the discrete energy levels.However... Quantum confinement is recognized to be an inherent property in low-dimensional structures.Traditionally,it is believed that the carriers trapped within the well cannot escape due to the discrete energy levels.However,our previous research has revealed efficient carrier escape in low-dimensional structures,contradicting this conventional understanding.In this study,we review the energy band structure of quantum wells along the growth direction considering it as a superposition of the bulk material dispersion and quantization energy dispersion resulting from the quantum confinement across the whole Brillouin zone.By accounting for all wave vectors,we obtain a certain distribution of carrier energy at each quantized energy level,giving rise to the energy subbands.These results enable carriers to escape from the well under the influence of an electric field.Additionally,we have compiled a comprehensive summary of various energy band scenarios in quantum well structures relevant to carrier transport.Such a new interpretation holds significant value in deepening our comprehension of low-dimensional energy bands,discovering new physical phenomena,and designing novel devices with superior performance. 展开更多
关键词 energy band quantum confinement type-I quantum wells low-dimensional structures
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An advanced theoretical approach to study super-multiperiod superlattices:theory vs experiments
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作者 Alexander Sergeevich Dashkov Semyon Andreevich Khakhulin +9 位作者 Dmitrii Alekseevich Shapran Gennadii Fedorovich Glinskii Nikita Andreevich Kostromin Alexander Leonidovich Vasiliev Sergey Nikolayevich Yakunin Oleg Sergeevich Komkov Evgeniy Viktorovich Pirogov Maxim Sergeevich Sobolev Leonid Ivanovich Goray Alexei Dmitrievich Bouravleuv 《Journal of Semiconductors》 EI CAS CSCD 2024年第2期57-66,共10页
A new theoretical method to study super-multiperiod superlattices has been developed.The method combines the precision of the 8-band kp-method with the flexibility of the shooting method and the Monte Carlo approach.T... A new theoretical method to study super-multiperiod superlattices has been developed.The method combines the precision of the 8-band kp-method with the flexibility of the shooting method and the Monte Carlo approach.This method was applied to examine the finest quality samples of super-multiperiod Al_(0.3)Ga_(0.7)As/GaAs superlattices grown by molecular beam epitaxy.The express photoreflectance spectroscopy method was utilized to validate the proposed theoretical method.For the first time,the accurate theoretical analysis of the energy band diagram of super-multiperiod superlattices with experimental verification has been conducted.The proposed approach highly accurately determines transition peak positions and enables the calculation of the energy band diagram,transition energies,relaxation rates,and gain estimation.It has achieved a remarkably low 5%error compared to the commonly used method,which typically results in a 25%error,and allowed to recover the superlattice parameters.The retrieved intrinsic parameters of the samples aligned with XRD data and growth parameters.The proposed method also accurately predicted the escape of the second energy level for quantum well thicknesses less than 5 nm,as was observed in photoreflectance experiments.The new designs of THz light-emitting devices operating at room temperature were suggested by the developed method. 展开更多
关键词 super-multiperiod superlattice photoreflectance spectroscopy Kane model kp-method energy band diagram light amplifiers
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Highly Sensitive Photodetectors Based on WS_(2) Quantum Dots/GaAs Heterostructures
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作者 LI Xianshuai LIN Fengyuan +4 位作者 HOU Xiaobing LI Kexue LIAO Lei HAO Qun WEI Zhipeng 《发光学报》 EI CAS CSCD 北大核心 2024年第10期1699-1706,共8页
The performance of the photodetector is significantly impacted by the inherent surface faults in GaAs nanowires(NWs).We combined three-dimensional(3D)gallium arsenide nanowires with zero-dimensional(0D)WS_(2) quantum ... The performance of the photodetector is significantly impacted by the inherent surface faults in GaAs nanowires(NWs).We combined three-dimensional(3D)gallium arsenide nanowires with zero-dimensional(0D)WS_(2) quantum dot(QDs)materials in a simple and convenient way to form a heterogeneous structure.Various performance enhancements have been realized through the formation of typeⅡenergy bands in heterostructures,opening up new research directions for the future development of photodetector devices.This work successfully fabricated a high-sensitivity photodetector based on WS_(2)QDs/GaAs NWs heterostructure.Under 660 nm laser excitation,the photodetector exhibits a responsivity of 368.07 A/W,a detectivity of 2.7×10^(12)Jones,an external quantum efficiency of 6.47×10^(2)%,a low-noise equivalent power of 2.27×10^(-17)W·Hz^(-1/2),a response time of 0.3 s,and a recovery time of 2.12 s.This study provides a new solution for the preparation of high-performance GaAs detectors and promotes the development of optoelectronic devices for GaAs NWs. 展开更多
关键词 GaAs nanowires WS_(2) quantum dots PHOTODETECTORS type-Ⅱenergy band structure
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Discrimination of Motor Imagery Patterns by Electroencephalogram Phase Synchronization Combined With Frequency Band Energy 被引量:4
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作者 Chuanwei Liu Yunfa Fu +3 位作者 Jun Yang Xin Xiong Huiwen Sun Zhengtao Yu 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2017年第3期551-557,共7页
Central nerve signal evoked by thoughts can be directly used to control a robot or prosthetic devices without the involvement of the peripheral nerve and muscles.This is a new strategy of human-computer interaction.A ... Central nerve signal evoked by thoughts can be directly used to control a robot or prosthetic devices without the involvement of the peripheral nerve and muscles.This is a new strategy of human-computer interaction.A method of electroencephalogram(EEG) phase synchronization combined with band energy was proposed to construct a feature vector for pattern recognition of brain-computer interaction based on EEG induced by motor imagery in this paper,rhythm and beta rhythm were first extracted from EEG by band pass filter and then the frequency band energy was calculated by the sliding time window;the instantaneous phase values were obtained using Hilbert transform and then the phase synchronization feature was calculated by the phase locking value(PLV) and the best time interval for extracting the phase synchronization feature was searched by the distribution of the PLV value in the time domain.Finally,discrimination of motor imagery patterns was performed by the support vector machine(SVM).The results showed that the phase synchronization feature more effective in4s-7s and the correct classification rate was 91.4%.Compared with the results achieved by a single EEG feature related to motor imagery,the correct classification rate was improved by 3.5 and4.3 percentage points by combining phase synchronization with band energy.These indicate that the proposed method is effective and it is expected that the study provides a way to improve the performance of the online real-time brain-computer interaction control system based on EEG related to motor imagery. 展开更多
关键词 Brain-computer interaction(BCI) electroencephalogram(EEG) frequency band energy motor imagery phase synchronization
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Electronic band energy of a bent ZnO piezoelectric semiconductor nanowire 被引量:4
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作者 Wanli YANG Yuantai HU E.N.PAN 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2020年第6期833-844,共12页
The electric band energy variation in a bent piezoelectric semiconductor(PSC) nanowire of circular cross-section induced by the mechanical force is analyzed based on a six-band k · p method. The electric-mechanic... The electric band energy variation in a bent piezoelectric semiconductor(PSC) nanowire of circular cross-section induced by the mechanical force is analyzed based on a six-band k · p method. The electric-mechanical fields are first obtained analytically in a cantilever bent PSC nanowire by solving the fully-coupled electro-mechanical equations. Then, the band energy is acquired numerically via the six-band Hamiltonian.By considering further the nonlinear coupling between the piezoelectric and semiconducting quantities, the contribution of the redistribution carriers to the electric field is analyzed from the Gauss’ s law. Numerical examples are carried out for an n-type Zn O nanowire in different locations induced by an applied concentrated end force. They include the electric potential, heavy hole(HH), light hole(LH), spin-orbit split-off(SO),and conduction band(CB) edges along the axial and thickness directions. Our results show that the applied force has a significant effect on the band energies. For instance, on the bottom surface along the axial direction, the bandgaps near the fixed end are greater than those near the loading end, and this trend is reversed on the top surface. Moreover,at a fixed axial location, the energy level of the lower side can be enhanced by applying a bending force at the end. The present results could be of significant guidance to the electronic devices and piezotronics. 展开更多
关键词 piezoelectric semiconductor(PSC) mechanical bending energy band ZNO
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Electric potential and energy band in ZnO nanofiber tuned by local mechanical loading 被引量:2
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作者 Shuaiqi FAN Ziguang CHEN 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2021年第6期787-804,共18页
Recent success in strain engineering has triggered tremendous interest in its study and potential applications in nanodevice design. In this paper, we establish a coupled piezoelectric/semiconducting model for a wurtz... Recent success in strain engineering has triggered tremendous interest in its study and potential applications in nanodevice design. In this paper, we establish a coupled piezoelectric/semiconducting model for a wurtzite structure ZnO nanofiber under the local mechanical loading. The energy band structure tuned by the local mechanical loading and local length is calculated via an eight-band k·p method, which includes the coupling of valance and conduction bands. Poisson's effect on the distribution of electric potential inversely depends on the local mechanical loading. Numerical results reveal that both the applied local mechanical loading and the local length exhibit obvious tuning effects on the electric potential and energy band. The band gap at band edges varies linearly with the applied loading. Changing the local length shifts the energy band which is far away from the band edges. This study will be useful in the electronic and optical enhancement of semiconductor devices. 展开更多
关键词 piezoelectric semiconductor(PS) local mechanical loading strain engineering energy band
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Crystal Structure, Energy Band and Optical Properties of Phosphate In(PO_3)_3 被引量:1
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作者 CHENG Wen-Dan WU Dong-Sheng +3 位作者 ZHANG Hao GONG Ya-Jing ZHU Jing TONG Hua-Nan 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2005年第12期1468-1475,共8页
The crystal of the title compound (InP3O9, Mr = 351.73) has been prepared and structurally determined by X-ray single-crystal diffraction. It crystallizes in the monoclinic system, space group Cc with a = 13.545(6... The crystal of the title compound (InP3O9, Mr = 351.73) has been prepared and structurally determined by X-ray single-crystal diffraction. It crystallizes in the monoclinic system, space group Cc with a = 13.545(6), b = 19.603(7), c = 9.672(4)A, β= 127.196(4)°, V= 2045.6(14) ,A^3 and Z = 12. The compound, with a three-fold superstructure, has two kinds of infinite chains of PO4 tetrahedra along the c axis. The absorption and luminescence spectra of In(PO3)3 powder have been measured. The calculated results of crystal energy band structure by DFT indicate that the solid state is kind of insulator. What is more, the bonding and optical properties were also investigated with the CASTEP code. 展开更多
关键词 crystal structure energy band optical properties
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Frequency in Middle of Magnon Band Gap in a Layered Ferromagnetic Superlattice 被引量:1
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作者 邱荣科 赵健 应彩虹 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第12期1144-1150,共7页
The frequency in middle of magnon energy band in a five-layer ferromagnetic superlattice is studied by using the linear spin-wave approach and Green's function technique. It is found that four energy gaps and corresp... The frequency in middle of magnon energy band in a five-layer ferromagnetic superlattice is studied by using the linear spin-wave approach and Green's function technique. It is found that four energy gaps and corresponding four frequencie in middle of energy gaps exist in the magnon band along Kx direction perpendicular to the superlattice plane. The spin quantum numbers and the interlayer exchange couplings all affect the four frequencies in middle of the energy gaps. When all interlayer exchange couplings are same, the effect of spin quantum numbers on the frequency wg1 in middle of the energy gap Δw12 is complicated, and the frequency wg1 depends on the match of spin quantum numbers in each layer. Meanwhile, the frequencies wg2, wg3, and wg4 in middle of other energy gaps increase monotonously with increasing spin quantum numbers. When the spin quantum numbers in each layer are same, the frequencies wg1, wg2, wg3, and wg4 all increase monotonously with increasing interlayer exchange couplings. 展开更多
关键词 layered ferromagnetic superlattice magnon energy band frequency in middle of the magnon energy gap spin quantum number interlayer exchange couplings
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Speech Resampling Detection Based on Inconsistency of Band Energy
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作者 Zhifeng Wang Diqun Yan +2 位作者 Rangding Wang Li Xiang Tingting Wu 《Computers, Materials & Continua》 SCIE EI 2018年第8期247-259,共13页
Speech resampling is a typical tempering behavior,which is often integrated into various speech forgeries,such as splicing,electronic disguising,quality faking and so on.By analyzing the principle of resampling,we fou... Speech resampling is a typical tempering behavior,which is often integrated into various speech forgeries,such as splicing,electronic disguising,quality faking and so on.By analyzing the principle of resampling,we found that,compared with natural speech,the inconsistency between the bandwidth of the resampled speech and its sampling ratio will be caused because the interpolation process in resampling is imperfect.Based on our observation,a new resampling detection algorithm based on the inconsistency of band energy is proposed.First,according to the sampling ratio of the suspected speech,a band-pass Butterworth filter is designed to filter out the residual signal.Then,the logarithmic ratio of band energy is calculated by the suspected speech and the filtered speech.Finally,with the logarithmic ratio,the resampled and original speech can be discriminated.The experimental results show that the proposed algorithm can effectively detect the resampling behavior under various conditions and is robust to MP3 compression. 展开更多
关键词 Resampling detection logarithmic ratio band energy robustness
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Energy Band Structure of Alq_3/TCAQ Heterostructure Complex Film Determined by Surface Photovoltage Spectroscopy(SPS)
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作者 CAO Ya-an, SONG Qing, MENG Qing-ju, CAO Chang-sheng CHEN Chun-hai, BAI Yu-bai, LI Tie-jin and YAO Jian-nian (Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100101, P. R. China Department of Chemistry, Jilin Uni 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2000年第4期328-333,共6页
8-Hydroxyquinoling aluminum (Alq3) and 11, 11, 12, 12-tetracyano-9, 10-anthraquino dimethane(TCAQ) monolayer films and their heterostructure complex films were prepared by a vacuum deposition method. By means of surfa... 8-Hydroxyquinoling aluminum (Alq3) and 11, 11, 12, 12-tetracyano-9, 10-anthraquino dimethane(TCAQ) monolayer films and their heterostructure complex films were prepared by a vacuum deposition method. By means of surface photovoltage spectroscopy (SPS) and electric field-induced surface photovoltage spectroscopy (EFISPS), the band gaps of TCAQ and Alq3 monolayer films and the properties of the Alq3/TCAQ bilayer film were investigated. By analysing the mechanism and the results of the SPS and the EFISPS, a reasonable energy band structure of the Alq3/TCAQ complex film was roughly determined. 展开更多
关键词 Alq_3 TCAQ Complex film SPS Energy band structure
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Electronic band gap and transport in graphene superlattice with a Gaussian profile potential voltage
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作者 张玉萍 尹贻恒 +1 位作者 吕欢欢 张会云 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第2期443-447,共5页
We study the electronic properties for the graphene-based one-dimensional superlattices, whose potential voltages vary according to the envelope of a Gaussian function. It is found that an unusual Dirac point exists a... We study the electronic properties for the graphene-based one-dimensional superlattices, whose potential voltages vary according to the envelope of a Gaussian function. It is found that an unusual Dirac point exists and its location is exactly associated with a zero-averaged wave number (zero-re) gap. This zero-k gap is less sensitive to incident angle and lattice constants, properties opposing those of Bragg gap. The defect mode appearing inside the zero-l gap has an effect on transmission, conductance, and shot noise, which will be useful for further investigation. 展开更多
关键词 graphene superlattice Gaussian profile energy band
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Unconventional Energy Bands and Chirality of Ultracold Atoms in Trilayer Honeycomb Lattice
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作者 HOU Jing-Min 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第8期247-250,共4页
We investigate ultracold fermionic atoms in the trilayer honeycomb lattice. In the low energy approximation, we derive an effective Hamiltonian for pseudospins. The energy spectrum shows a cubic form of the wavevector... We investigate ultracold fermionic atoms in the trilayer honeycomb lattice. In the low energy approximation, we derive an effective Hamiltonian for pseudospins. The energy spectrum shows a cubic form of the wavevector and is gapless. The quasiparticles and quasiholes are ehiral and show Berry's phase π when the wavevector adiabatically evolves along a closed circle, Furthermore, the experimental detection of the energy spectrum is proposed with Bragg scattering techniques. 展开更多
关键词 ultracold atoms honeycomb optical lattice energy bands
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The Influence of Muffin-tin Approximation on Energy Band Gap
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作者 WU Zhi-jian MENG Qing-bo ZHANG Si-yuan 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 1998年第3期82-86,共5页
The influence of muffin tin approximation on energy band gap was studied using LMTO ASA ( Linear Muffin Tin Orbital Atomic Sphere Approximation) approach. Since the diverse data are available for LaX(X=N, P, As, ... The influence of muffin tin approximation on energy band gap was studied using LMTO ASA ( Linear Muffin Tin Orbital Atomic Sphere Approximation) approach. Since the diverse data are available for LaX(X=N, P, As, Sb), they are presented in our research as an example in order to test the reliability of our results. Four groups of muffin tin radii were chosen, they were the fitted muffin tin radii based on the optical properties of the crystals (the first), 1∶1 for La∶X(the second), 1 5∶1 for La∶X(the third), and a group of radii derived by making the charge in the interstitial space to be zero(the fourth). The results show that the fitted muffin tin radii (the first group) give the best results compared with experimental values, and the predicted energy band gaps are very sensitive to the choice of muffin tin radius in comparison with the other groups. The second and the third delivered results somewhere in between, while the fourth provided the worst results compared with the other groups. For the same crystal, with the increase of muffin tin radius of lanthanum, the calculated energy band gaps decreased, going from semi conductor to semi metal. This again clearly indicated the sensitivity of energy band structure on muffin tin approximation. 展开更多
关键词 LMTO Energy band structure Muffin tin approximation
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Energy band adjustment of 808 nm GaAs laser power converters via gradient doping
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作者 Yingjie Zhao Shan Li +2 位作者 Huixue Ren Shaojie Li Peide Han 《Journal of Semiconductors》 EI CAS CSCD 2021年第3期73-79,共7页
The gradient doping regions were employed in the emitter layer and the base layer of GaAs based laser power converters(LPCs).Silvaco TCAD was used to numerically simulate the linear gradient doping and exponential gra... The gradient doping regions were employed in the emitter layer and the base layer of GaAs based laser power converters(LPCs).Silvaco TCAD was used to numerically simulate the linear gradient doping and exponential gradient doping structure,and analyze the transport process of photogenerated carriers.Energy band adjustment via gradient doping improved the separation and transport efficiency of photogenerated carriers and reduced the total recombination rate of GaAs LPCs.Compared with traditional structure of LPCs,the photoelectric conversion efficiency of LPCs with linear and exponential gradient doping structure were improved from 52.7%to 57.2%and 57.7%,respectively,under 808 nm laser light at the power density of 1 W/cm^(2). 展开更多
关键词 gradient doping laser power converters(LPCs) energy band adjustment numerical simulation
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Electric Anisotropy and Two-dimensional Energy Band of Undoped and Heavily Doped Polyacetylene
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《Chemical Research in Chinese Universities》 SCIE CAS CSCD 1995年第3期228-231,共4页
ased on the known crystal data , we used the EHMACC(EHMO/CO) methodto calculate the twotlimensional energy band of both undoped and heavily iodine-doped polyacetylene (PA). The results show that (1 ) I-doping obviousl... ased on the known crystal data , we used the EHMACC(EHMO/CO) methodto calculate the twotlimensional energy band of both undoped and heavily iodine-doped polyacetylene (PA). The results show that (1 ) I-doping obviously reducesthe niagnitudes of Eg , Egi; (2) in the conducting process along the direction per-pendicular to PA chain , the P-type AO of iodine plays a very important role, i- e. ,the conducting bridge to transport the charge between the two neighbor PA chains.I-doping reniarkably increases σ_T value while the conducting process will reduce theratio magnitude of σ/σ. Therefore, heavily I-doping makes PA change fromsimeconductor to conductor which obviously has 2-D conductive ability. 展开更多
关键词 Conductive polymer 2-D energy band Electric anisotropy
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Energy band and charge-carrier engineering in skutterudite thermoelectric materials
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作者 Zhiyuan Liu Ting Yang +2 位作者 Yonggui Wang Ailin Xia Lianbo Ma 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第10期208-219,共12页
The binary CoSb_(3) skutterudite thermoelectric material has high thermal conductivity due to the covalent bond between Co and Sb, and the thermoelectric figure of merit, ZT, is very low. The thermal conductivity of C... The binary CoSb_(3) skutterudite thermoelectric material has high thermal conductivity due to the covalent bond between Co and Sb, and the thermoelectric figure of merit, ZT, is very low. The thermal conductivity of CoSb_(3) materials can be significantly reduced through phonon engineering, such as low-dimensional structure, the introduction of nano second phases,nanointerfaces or nanopores, which greatly improves their ZT values. The phonon engineering can optimize significantly the thermal transport properties of CoSb_(3)-based materials. However, the improvement of the electronic transport properties is not obvious, or even worse. Energy band and charge-carrier engineering can significantly improve the electronic transport properties of CoSb_(3)-based materials while optimizing the thermal transport properties. Therefore, the decoupling of thermal and electronic transport properties of CoSb_(3)-based materials can be realized by energy band and charge-carrier engineering. This review summarizes some methods of optimizing synergistically the electronic and thermal transport properties of CoSb_(3) materials through the energy band and charge-carrier engineering strategies. Energy band engineering strategies include band convergence or resonant energy levels caused by doping/filling. The charge-carrier engineering strategy includes the optimization of carrier concentration and mobility caused by doping/filling, forming modulation doped structures or introducing nano second phase. These strategies are effective means to improve performance of thermoelectric materials and provide new research ideas of development of high-efficiency thermoelectric materials. 展开更多
关键词 CoSb_(3)-based skutterudite materials energy band engineering charge-carrier engineering thermoelectric properties
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Band Edge Emission Improvement by Energy Transfer in HybridⅢ-Nitride/Organic Semiconductor Nanostructure
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作者 蒋府龙 刘亚莹 +9 位作者 李扬扬 陈鹏 刘斌 谢自力 修向前 华雪梅 韩平 施毅 张荣 郑有炓 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第10期132-135,共4页
GaN nanorods are fabricated using inductively coupled plasma etching with Ni nano-island masks. The poly [2- methoxy-5-(2-ethyl)hexoxy-l,4-phenylenevinylene] (MEH-PPV)/GaN-nanorod hybrid structure is fabricated by... GaN nanorods are fabricated using inductively coupled plasma etching with Ni nano-island masks. The poly [2- methoxy-5-(2-ethyl)hexoxy-l,4-phenylenevinylene] (MEH-PPV)/GaN-nanorod hybrid structure is fabricated by depositing the MEH-PPV film on the GaN nanorods by using the spin-coating process. In the hybrid structure, the spatial separation is minimized to achieve high-emciency non-radiative resonant energy transfer. Optical properties of a novel device consisting of MEH-PPV/GaN-nanorod hybrid structure is studied by analyzing photoluminescenee (PL) spectra. Compared with the pure GaN nanorods, the PL intensity of the band edge emission of GaN in the MEH-PPV/GaN-nanorods is enhanced as much as three times, and the intensity of the yellow band is suppressed slightly. The obtained results are analyzed by energy transfer between the GaN nanorods and the MEH-PPV. An energy transfer model is proposed to explain the phenomenon. 展开更多
关键词 GaN PPV MEH Nitride/Organic Semiconductor Nanostructure band Edge Emission Improvement by Energy Transfer in Hybrid by in
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