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排序方式: 共有532条查询结果,搜索用时 15 毫秒
21.
InAs/InP_(0.7)Sb_(0.3)热电子晶体管的电流增益及最高收集极电压 总被引:1,自引:1,他引:0
续竞存 《固体电子学研究与进展》1995,15(1):41-44
分析InAs/InP(0.7)Sb(0.3)热电子晶体管的电流增益β及最高收集极电压V(CM)。计算结果表明,β超过20,V(CM)接近1.5V。 相似文献
22.
Transparent p-n heterojunction diodes have been fabricated by p-type copper aluminum oxide (p-CuAlO2 + x) and n-type aluminum doped zinc oxide (n-Zn1 − xAlxO) thin films on glass substrates. The n-layers are deposited by sol-gel-dip-coating process from zinc acetate dihydrate (Zn(CH3COO)2·2H2O) and aluminum nitrate (Al(NO3)3·9H2O). Al concentration in the nominal solution is taken as 1.62 at %. P-layers are deposited onto the ZnO:Al-coated glass substrates by direct current sputtering process from a prefabricated CuAlO2 sintered target. The sputtering is performed in oxygen-diluted argon atmosphere with an elevated substrate temperature. Post-deposition oxygen annealing induces excess oxygen within the p-CuAlO2 + x films, which in turn enhances p-type conductivity of the layers. The device characterization shows rectifying current-voltage characteristics, confirming the proper formation of the p-n junction. The turn-on voltage is obtained around 0.8 V, with a forward-to-reverse current ratio around 30 at ± 4 V. The diode structure has a total thickness of 1.1 μm and the optical transmission spectra of the diode show almost 60% transmittance in the visible region, indicating its potential application in ‘invisible electronics’. Also the cost-effective procedures enable the large-scale production of these transparent diodes for diverse device applications. 相似文献
23.
Device quality CdTe films and junctions have been studied using low-temperature photoluminescence (PL) measurements. The behavior of the PL was studied as a function of the measurement temperature and excitation intensity. The CdTe films and junctions were prepared under various deposition conditions to determine the effect of film deposition and solar cell fabrication parameters, such as the effect of oxygen, and chloride treatment. A PL band located at 1.232 eV has been attributed to the presence of oxygen. This band is present only in as-deposited samples excited at the CdTe surface. Samples annealed in the presence of CdCl2 exhibit a single PL band located at 1.42 eV. A model explaining the behavior of these bands is presented. 相似文献
24.
R. Hunger M.V. Lebedev T. Schulmeyer A. Klein W. Jaegermann 《Thin solid films》2007,515(15):6112-6118
The junction formation of polycrystalline CuInSe2 absorbers (CIS) with thermally evaporated CdS was investigated by high-resolution synchrotron X-ray photoelectron spectroscopy. The chemistry and electronics of the interfaces of Cd partial electrolyte treated CIS (“wet” processed) and clean, decapped CIS (“dry” processed) were compared. A valence band offset of 0.96(10) eV was determined in both cases. The Cd(Se,OH) surface layer induced by the wet Cd partial electrolyte process does not significantly modify the band alignment at the CIS/CdS heterointerface from the “dry”, vacuum-processed CIS/CdS interface.During the stepwise interface formation the energy converting capability of the CIS/CdS heterojunction was assessed by in situ surface photovoltage measurements at room temperature. The evolution of the surface photovoltage significantly differs for the “wet” and the “dry” interfaces and is discussed in relation to the function in solar cell devices. 相似文献
25.
ZHENG Jian-bang REN Ju HOU Chao-qi 《半导体光子学与技术》2005,11(4):248-252,258
Using the electrochemical polymerization dye sensitization (ECDS) method, polyaniline (PAn), which is used as top region material in solar cells, is sensitized with direct blue dye(DS), and sensitized Al grid/DS-PAn/n-Si/Al heterojunction solar cells is prepared by ECDS. Influences of the ECDS on the absorption spectrum and the junction characteristics of the solar cell were discussed, and the output characteristics were measured. The results show that the absorption spectrum of the sensitized PAn films is much wider and stronger in Vis-range; the diode quality factor is about 6.3 and the height of latent barrier potential of p-n junction is 0.89 eV; the short-circuit current and the conversion efficiency of sensitized DS- PAn/Si heterojunction solar cells are greatly improved, which the short-circuit current can increase 6 times, the fill factor is 57% and the efficiency can reach 1.42 % under the illumination of 37.2 W/m^2 , respectively. 相似文献
26.
/ 《Solar Energy Materials & Solar Cells》2008,92(9):1099-1104
SnS/CdS heterojunction is a promising system for the fabrication of thin film solar cells. In our work, thin film SnS/CdS heterojunction was prepared by evaporating CdS and SnS films. The photovoltaic properties of the heterojunction were investigated with posttreatment of the window material treatment by CdCl2 for grain size enlargement. I–V characteristics in dark and at light were taken and figures of merit were evaluated. The efficiency with and without window layer treatment were about 0.08% and 0.05%, respectively, under 100 mW/cm2 intensity. To the best of our knowledge so far there has been no report on vacuum-evaporated SnS-based heterojunction with window material treatment by CdCl2. 相似文献
27.
The properties of poly-Si/GaAs layered films on Si for use in wide bandgap emitters for Si heterojunction bipolar transistors
(Si-HBTs), were studied. A smooth GaAs film surface grown on Si was obtained at low temperature (200° C) from the initial
stage of growth. The x-ray diffraction (XRD) results indicated that strong GaAs orientation (111) was obtained for the poly-Si/GaAs/Si-substrate
layered structure after annealing at 800° C for 20 sec. Secondary ion mass spectroscopy (SIMS) profiles indicated that impurity
diffusion from the GaAs layer into the p-type Si substrate was negligible at 800° C. The electrical characteristics forn-poly-Si/n-GaAs/p-Si-substrate heterojunction diodes were also investigated. 相似文献
28.
29.
新型发射极指组合结构功率SiGe HBT热分析 总被引:2,自引:0,他引:2
提出了一种发射极指分段和非均匀发射极指长、指间距组合的新型器件结构,以改善多指功率硅锗异质结双极晶体管(SiGe HBT)的热稳定性。考虑器件具有多层热阻,发展建立了相应的热传导模型。以十指功率SiGe HBT为例,运用有限元方法对其进行热模拟,得到三维温度分布。与传统发射极结构器件相比,新结构器件最高结温从416.3 K下降到405 K,各个发射指上的高低温差从7 K~8 K下降为1.5 K~3 K,热阻值下降14.67 K/W,器件整体温度分布更加均匀。 相似文献
30.
This paper presents a dual approach for a coherent determination and validation of heterostructure bipolar transistor (HBT) thermal impedance. This study relies both on an experimental characterization method and a 3D finite element simulation approach. One section reminds briefly the experimental approach. Another describes the 3D device modeling used for the physics-based thermal simulation. Thereafter, details on the reduction method used for the numerical computation of the thermal impedance are given. As complement to pure thermal simulation, an electrothermal distributed model is proposed and gives an interpretation of the distributed effects in multi-finger devices. 相似文献