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电推进是利用电能加热、离解和加速工质,使其形成高速射流而产生推力的技术。与化学推进相比,电推进具有比冲高、推力小、能重复启动、重量轻和寿命长等特点,因而电推进可用作航天器的姿态控制、轨道转移和提升、轨道修正、阻力补偿、位置保持、重新定位、离轨处理、宇宙探测和星际航行等任务。 相似文献
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Factors influencing the performance of paintable carbon-based perovskite solar cells fabricated in ambient air 下载免费PDF全文
To date, many efforts have been made to improve the performance of paintable carbon-based(PC-based) perovskite solar cells(PSCs). Though great progress has been achieved, their power conversion efficiencies are still relatively low compared with hole-transport-materials-based PSCs. General research on influencing factors of performance in PC-based PSCs is still insufficient. In this work, PC-based PSCs were fabricated in ambient air and four groups of controlled experiments were performed in which the PbI_2 layers were prepared with or without antisolvent extraction treatment. These four groups of experiments were designed to find out the effect of different influencing factors on PC-based PSCs performance,for example, PbI_2 residual, the surface morphology of the perovskite film, the surface roughness of the perovskite film, and the contact status of the perovskite/carbon electrode interface. With a systematic analysis, we demonstrated that the contact status of the perovskite/carbon electrode interface played a vital role in PC-based PSCs, and a flat, smooth perovskite surface could help to improve this contact status significantly. Besides, on the precondition of a poor contact interface, no PbI_2 residual and a good surface morphology only brought limited benefits to the performances of PC-based PSCs. 相似文献
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激光束通过双光栅衍射,衍射光束重叠形成光拍,光拍信号通过硅光电池进行光电转换,得到的信号电流的频率等于多普勒频移.信号电流经I/V转换、反函数电路和微分及计算电路运算后,可以确定多普勒频移,从而确定动光栅的运动速度.测量了音叉在换能器的作用下做微振动时动光栅的瞬时速度. 相似文献
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High-sensitive phototransistor based on vertical HfSe2/MoS2 heterostructure with broad-spectral response 下载免费PDF全文
Van der Waals heterostructures based on the two-dimensional (2D) semiconductor materials have attracted increasing attention due to their attractive properties. In this work, we demonstrate a high-sensitive back-gated phototransistor based on the vertical HfSe2/MoS2 heterostructure with a broad-spectral response from near-ultraviolet to near-infrared and an efficient gate tunability for photoresponse. Under bias, the phototransistor exhibits high responsivity of up to 1.42×103 A/W, and ultrahigh specific detectivity of up to 1.39×1015 cm·Hz1/2·W-1. Moreover, it can also operate under zero bias with remarkable responsivity of 10.2 A/W, relatively high specific detectivity of 1.43×1014 cm·Hz1/2·W-1, ultralow dark current of 1.22 fA, and high on/off ratio of above 105. These results should be attributed to the fact that the vertical HfSe2/MoS2 heterostructure not only improves the broadband photoresponse of the phototransistor but also greatly enhances its sensitivity. Therefore, the heterostructure provides a promising candidate for next generation high performance phototransistors. 相似文献
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采用AFORS-HET软件对CsGeI3空穴传输层(Hole Transport Material, HTM)平面异质结钙钛矿太阳电池进行了模拟,TiO2作为电子传输层,CH3NH3PbI3作为光吸收层,C作为背电极,分别讨论了钙钛矿光吸收层厚度、缺陷浓度,光吸收层/HTM界面态密度和HTM对太阳电池性能参数的影响.模拟优化得到CsGeI3 HTM的PSCs最佳性能参数为:Voc=1.199 V,Jsc=22.2 mA·cm-2,FF=86.22;,PCE=22.95;,效率虽略低于spiro作为HTM的器件,但考虑生产工艺和制备成本,CsGeI3作为HTM的PSCs将具有更好的应用前景. 相似文献
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采用AFORS-HET软件对以B-γ-CsSnI3作为光吸收层的平面异质结钙钛矿太阳能电池结构进行了模拟优化,其中TiO2作为电子传输层,Spiro-OMeTAD作为空穴传输层,讨论了钙钛矿太阳能电池光吸收层以及空穴传输层的各种参数对太阳能电池性能的影响.模拟优化得到B-γ-CsSnI3的PSCs最佳性能参数为:Voc=1.18 V,Jsc=24.48 mA/cm2,FF=80.04;,PCE=23.15;,效率虽略低于以CH3NH3PbI3作为光吸收层的钙钛矿太阳能电池,但考虑铅的毒性和钙钛矿电池的稳定性,以B-γ-CsSnI3作为光吸收层的PSCs将具有更好的应用前景. 相似文献
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通过考虑体散射、界面电荷的库仑散射以及 Al2O3/InxGa1-xAs 界面粗糙散射等主要散射机理, 建立了以 Al2O3为栅介质InxGa1-xAs n 沟金属-氧化物-半导体场效应晶体管 (nMOSFETs) 反型沟道电子迁移率模型, 模拟结果与实验数据有好的符合. 利用该模型分析表明, 在低至中等有效电场下, 电子迁移率主要受界面电荷库仑散射的影响; 而在强场下, 电子迁移率则取决于界面粗糙度散射. 降低界面态密度, 减小 Al2O3/InxGa1-xAs 界面粗糙度, 适当提高In含量并控制沟道掺杂在合适值是提高 InGaAs nMOSFETs 反型沟道电子迁移率的主要途径.
关键词:
InGaAs
MOSFET
反型沟道电子迁移率
散射机理 相似文献
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Thin film solar cells have the potential to significantly reduce the cost of photovoltaics. Light trapping is crucial to such a thin film silicon solar cell because of a low absorption coefficient due to its indirect band gap. In this paper, we investigate the suitability of surface plasmon resonance Ag nanoparticles for enhancing optical absorption in the thin film solar cell. For evaluating the transmittance capability of Ag nanoparticles and the conventional antireflection film, an enhanced transmittance factor is introduced. We find that under the solar spectrum AM1.5, the transmittance of Ag nanoparticles with radius over 160 nm is equivalent to that of conventional textured antireflection film, and its effect is better than that of the planar antireflection film. The influence of the surrounding medium is also discussed. 相似文献