The results of an experimental study of long-term relaxation of the photoelectret state of polycrystalline CdTe:(Ag, Cu, Cd) and Sb<sub>2</sub>Se<sub>3</sub>:Se films with an anomalous photovol...The results of an experimental study of long-term relaxation of the photoelectret state of polycrystalline CdTe:(Ag, Cu, Cd) and Sb<sub>2</sub>Se<sub>3</sub>:Se films with an anomalous photovoltaic property are presented. In such films, the residual photovoltage is caused by the separation of photocarriers by the built-in electrostatic field of the near-surface region of space charges and their asymmetric capture by deep levels of impurities or complexes, including impurity atoms and intrinsic defects, both in the bulk and on the surface of crystal grains. It has been shown that in activated films, a two-step exponential temporary relaxation of the initial photovoltage of the order of V<sub>APV</sub> ≈ (500-600) V is detected, and only 10% of it experiences long-term relaxation (t ≈ 100-120 min).展开更多
In this paper the fabrication technique of amorphous SnO2：（Zn, In） film is presented. The transmittance and gap-states distribution of the film are given. The experimental results of gap-states distribution are com...In this paper the fabrication technique of amorphous SnO2：（Zn, In） film is presented. The transmittance and gap-states distribution of the film are given. The experimental results of gap-states distribution are compared with the calculated results by using the facts of short range order and lattice vacancy defect of the gap states theory. The distribution of gap state has been proved to be discontinuous due to the short-range order of amorphous structure.展开更多
Presents the study on the law governing the occurrence of bistable state in the squeeze film damper supported rigid rotor system by theoretical calculations,the way q calculating the bistable state characteristics, th...Presents the study on the law governing the occurrence of bistable state in the squeeze film damper supported rigid rotor system by theoretical calculations,the way q calculating the bistable state characteristics, the analysis of bistable state characteristics using bearing parameter B and mass eccentricity U as basic parameters, and the ranges of B and U values established, and concludes that the occurrence of bistable state can be avoided provided design parameters are properly selected so that the B and U values are not in the ranges established. This makes it convenient to optimize the squeeze film damper design parameters.展开更多
We report a model of the carrier transport and the subgap density of states in a polycrystalline ZnO film for simulating a polycrystalline ZnO thin film transistor. This simple model considering the deep and the band ...We report a model of the carrier transport and the subgap density of states in a polycrystalline ZnO film for simulating a polycrystalline ZnO thin film transistor. This simple model considering the deep and the band tail states reproduces well the characteristics of polycrystalline ZnO thin film transistors. Furthermore, using the developed model, we study the effects of defect parameters on the electrical performances of the polycrystalline ZnO thin film transistors.展开更多
The estimate model for a nonlinear system of squeeze film damper (SFD) is described.The method of state variable filter (SVF) is used to estimate the coefficients of SFD.The factors which are critical to the estimate...The estimate model for a nonlinear system of squeeze film damper (SFD) is described.The method of state variable filter (SVF) is used to estimate the coefficients of SFD.The factors which are critical to the estimate accuracy are discussed展开更多
The optical reflectance and transmittance spectra in the wavelength range of 300-2500 nm are used to compute the absorption coefficient of zinc oxide films annealed at different post-annealing temperatures 400, 500 an...The optical reflectance and transmittance spectra in the wavelength range of 300-2500 nm are used to compute the absorption coefficient of zinc oxide films annealed at different post-annealing temperatures 400, 500 and 600°C.The values of the cross point between the curves of the real and imaginary parts of the optical conductivity ɑ_1 and ɑ_1 with energy axis of films exhibit values that correspond to optical gaps and are about 3.25-3.3 eV. The maxima of peaks in plots dR/dλ and dT/dλ versus wavelength of films exhibit optical gaps at about 3.12-3.25 eV.The values of the fundamental indirect band gap obtained from the Tauc model are at about 3.14-3.2 eV. It can be seen that films annealed at 600°C have the minimum indirect optical band gap at about 3.15 eV. The films annealed at 600°C have Urbach＇s energy minimum of 1.38 eV and hence have minimum disorder. The dispersion energy d of films annealed at 500°C has the minimum value of 43 eV.展开更多
The regeneration procedure of Q-state PbS particles in lead arachidate(PbAr)Langmuir-Blodgett films have been studied by means of UV-vis absorption, FT-IR spectra and quartz crystal microbalance(QCM) measurements.The ...The regeneration procedure of Q-state PbS particles in lead arachidate(PbAr)Langmuir-Blodgett films have been studied by means of UV-vis absorption, FT-IR spectra and quartz crystal microbalance(QCM) measurements.The results showed that the mole fraction of PbS particles in LB films was increased by immersing PbScontaining ArH LB films in a Pb￣(2+) buffer solution,followed by being reexposed to H_2S gas.展开更多
Thin film microbattery is a promising micropower source for its high energy density and good cell performances, and the application of fast lithium ion conducting solids as electrolytes is thus very important. （Li 0....Thin film microbattery is a promising micropower source for its high energy density and good cell performances, and the application of fast lithium ion conducting solids as electrolytes is thus very important. （Li 0.5 La 0.5 ）TiO3 （LLTO） thin film electrolytes for thin film microbattery were prepared onto Pt/Si substrates using magnetron sputtering. As-deposited LLTO thin films showed amorphous-like phases and when deposition temperature increases the ionic conductivity raises accordingly. The ionic conductivity of LLTO thin film reaches 8.7×10 -6 S/cm when the deposition temperature is 400℃, which shows that the LLTO thin films deposited by magnetron sputtering are suitable for application as an electrolyte for thin film microbattery.展开更多
针对背沟道刻蚀(Back Channel Etch,BCE)技术的非晶铟镓锌氧化物(a-IGZO)薄膜晶体管(Thin Film Transistor,TFTs),建立了一种高浓度掺杂态密度模型(High Concentration Doping Density Of States model,HCD-DOS model),并通过数值模拟...针对背沟道刻蚀(Back Channel Etch,BCE)技术的非晶铟镓锌氧化物(a-IGZO)薄膜晶体管(Thin Film Transistor,TFTs),建立了一种高浓度掺杂态密度模型(High Concentration Doping Density Of States model,HCD-DOS model),并通过数值模拟研究态密度关键参数对器件性能的影响,以此揭示a-IGZO TFTs中制备工艺对导电沟道修复的物理机理.首先,采用结合强度较高的钼/铜双层结构作为栅/源/漏电极,引入BCE方法制备了底栅顶接触(BottomGate Top-Contact,BG-TC)TFTs.其次,建立了适用于BCE技术的a-IGZO TFTs的HCD-DOS模型.随后,基于TCAD(Technology Computer Aided Design)仿真器对态密度关键参数进行数值研究,结果表明,不同态密度参数对a-IGZO TFTs器件转移特性曲线、电学特性以及沟道内部电子浓度分布的影响有所差异.最后,基于HCD-DOS模型探索SiO_(x)钝化层沉积和N_(2)O等离子体处理对器件内部机理的影响.研究发现,N2O等离子体处理对态密度分布和沟道载流子浓度有显著影响,进而导致阈值电压正向漂移.展开更多
The electrical and optical properties of the indium tin oxide （ITO）/epoxy composite exhibit dramatic variations as functions of the ITO composition and ITO particle size. Sharp increases in the conductivity in the v...The electrical and optical properties of the indium tin oxide （ITO）/epoxy composite exhibit dramatic variations as functions of the ITO composition and ITO particle size. Sharp increases in the conductivity in the vicinity of a critical volume fraction have been found within the framework of percolation theory. A conductive and insulating transition model is extracted by the ITO particle network in the SEM image, and verified by the resistivity dependence on the temperature. The dependence of the optical transmittance on the particle size was studied. Further decreasing the ITO particle size could further improve the percolation threshold and light transparency of the composite film.展开更多
Transport characteristics of single crystal bismuth films on Si（111）-7×7 are found to be metallic or insulating at temperature below or above Tc, respectively. The transition temperature Tc decreases as the fil...Transport characteristics of single crystal bismuth films on Si（111）-7×7 are found to be metallic or insulating at temperature below or above Tc, respectively. The transition temperature Tc decreases as the film thickness increases. By combining thickness dependence of the films resistivity, we find the insulating behaviour results from the states inside film, while the metallic behaviour originates from the interface states. We show that quantum size effect in a Bi film, such as the semimetal-to-semiconductor transition, is only observable at a temperature higher than Tc.展开更多
文摘The results of an experimental study of long-term relaxation of the photoelectret state of polycrystalline CdTe:(Ag, Cu, Cd) and Sb<sub>2</sub>Se<sub>3</sub>:Se films with an anomalous photovoltaic property are presented. In such films, the residual photovoltage is caused by the separation of photocarriers by the built-in electrostatic field of the near-surface region of space charges and their asymmetric capture by deep levels of impurities or complexes, including impurity atoms and intrinsic defects, both in the bulk and on the surface of crystal grains. It has been shown that in activated films, a two-step exponential temporary relaxation of the initial photovoltage of the order of V<sub>APV</sub> ≈ (500-600) V is detected, and only 10% of it experiences long-term relaxation (t ≈ 100-120 min).
基金Project supported by the Program A for Science and Technology of Education Bureau of Fujian Province of China (Grant No. JA08210)
文摘In this paper the fabrication technique of amorphous SnO2：（Zn, In） film is presented. The transmittance and gap-states distribution of the film are given. The experimental results of gap-states distribution are compared with the calculated results by using the facts of short range order and lattice vacancy defect of the gap states theory. The distribution of gap state has been proved to be discontinuous due to the short-range order of amorphous structure.
文摘Presents the study on the law governing the occurrence of bistable state in the squeeze film damper supported rigid rotor system by theoretical calculations,the way q calculating the bistable state characteristics, the analysis of bistable state characteristics using bearing parameter B and mass eccentricity U as basic parameters, and the ranges of B and U values established, and concludes that the occurrence of bistable state can be avoided provided design parameters are properly selected so that the B and U values are not in the ranges established. This makes it convenient to optimize the squeeze film damper design parameters.
基金supported by the Fundamental Research Funds for the Central Universities,China(Grant No.K50510250001)
文摘We report a model of the carrier transport and the subgap density of states in a polycrystalline ZnO film for simulating a polycrystalline ZnO thin film transistor. This simple model considering the deep and the band tail states reproduces well the characteristics of polycrystalline ZnO thin film transistors. Furthermore, using the developed model, we study the effects of defect parameters on the electrical performances of the polycrystalline ZnO thin film transistors.
文摘The estimate model for a nonlinear system of squeeze film damper (SFD) is described.The method of state variable filter (SVF) is used to estimate the coefficients of SFD.The factors which are critical to the estimate accuracy are discussed
文摘The optical reflectance and transmittance spectra in the wavelength range of 300-2500 nm are used to compute the absorption coefficient of zinc oxide films annealed at different post-annealing temperatures 400, 500 and 600°C.The values of the cross point between the curves of the real and imaginary parts of the optical conductivity ɑ_1 and ɑ_1 with energy axis of films exhibit values that correspond to optical gaps and are about 3.25-3.3 eV. The maxima of peaks in plots dR/dλ and dT/dλ versus wavelength of films exhibit optical gaps at about 3.12-3.25 eV.The values of the fundamental indirect band gap obtained from the Tauc model are at about 3.14-3.2 eV. It can be seen that films annealed at 600°C have the minimum indirect optical band gap at about 3.15 eV. The films annealed at 600°C have Urbach＇s energy minimum of 1.38 eV and hence have minimum disorder. The dispersion energy d of films annealed at 500°C has the minimum value of 43 eV.
文摘The regeneration procedure of Q-state PbS particles in lead arachidate(PbAr)Langmuir-Blodgett films have been studied by means of UV-vis absorption, FT-IR spectra and quartz crystal microbalance(QCM) measurements.The results showed that the mole fraction of PbS particles in LB films was increased by immersing PbScontaining ArH LB films in a Pb￣(2+) buffer solution,followed by being reexposed to H_2S gas.
文摘Thin film microbattery is a promising micropower source for its high energy density and good cell performances, and the application of fast lithium ion conducting solids as electrolytes is thus very important. （Li 0.5 La 0.5 ）TiO3 （LLTO） thin film electrolytes for thin film microbattery were prepared onto Pt/Si substrates using magnetron sputtering. As-deposited LLTO thin films showed amorphous-like phases and when deposition temperature increases the ionic conductivity raises accordingly. The ionic conductivity of LLTO thin film reaches 8.7×10 -6 S/cm when the deposition temperature is 400℃, which shows that the LLTO thin films deposited by magnetron sputtering are suitable for application as an electrolyte for thin film microbattery.
文摘针对背沟道刻蚀(Back Channel Etch,BCE)技术的非晶铟镓锌氧化物(a-IGZO)薄膜晶体管(Thin Film Transistor,TFTs),建立了一种高浓度掺杂态密度模型(High Concentration Doping Density Of States model,HCD-DOS model),并通过数值模拟研究态密度关键参数对器件性能的影响,以此揭示a-IGZO TFTs中制备工艺对导电沟道修复的物理机理.首先,采用结合强度较高的钼/铜双层结构作为栅/源/漏电极,引入BCE方法制备了底栅顶接触(BottomGate Top-Contact,BG-TC)TFTs.其次,建立了适用于BCE技术的a-IGZO TFTs的HCD-DOS模型.随后,基于TCAD(Technology Computer Aided Design)仿真器对态密度关键参数进行数值研究,结果表明,不同态密度参数对a-IGZO TFTs器件转移特性曲线、电学特性以及沟道内部电子浓度分布的影响有所差异.最后,基于HCD-DOS模型探索SiO_(x)钝化层沉积和N_(2)O等离子体处理对器件内部机理的影响.研究发现,N2O等离子体处理对态密度分布和沟道载流子浓度有显著影响,进而导致阈值电压正向漂移.
基金supported by the National Natural Science Foundation of China(Grant Nos.61222501 and 61335004)
文摘The electrical and optical properties of the indium tin oxide （ITO）/epoxy composite exhibit dramatic variations as functions of the ITO composition and ITO particle size. Sharp increases in the conductivity in the vicinity of a critical volume fraction have been found within the framework of percolation theory. A conductive and insulating transition model is extracted by the ITO particle network in the SEM image, and verified by the resistivity dependence on the temperature. The dependence of the optical transmittance on the particle size was studied. Further decreasing the ITO particle size could further improve the percolation threshold and light transparency of the composite film.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.10874217 and 10427402)the National Basic Research Program of China(973 Program)(Grant No.2006CB933000)
文摘Transport characteristics of single crystal bismuth films on Si（111）-7×7 are found to be metallic or insulating at temperature below or above Tc, respectively. The transition temperature Tc decreases as the film thickness increases. By combining thickness dependence of the films resistivity, we find the insulating behaviour results from the states inside film, while the metallic behaviour originates from the interface states. We show that quantum size effect in a Bi film, such as the semimetal-to-semiconductor transition, is only observable at a temperature higher than Tc.
