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144.
Open-circuit voltage analysis of p-i-n type amorphous silicon solar cells deposited at low temperature 下载免费PDF全文
This paper identifies the contributions of p-a-SiC:H layers and i-a-Si:H layers to the open circuit voltage of p-i-n type a-Si:H solar cells deposited at a low temperature of 125 C.We find that poor quality p-a-SiC:H films under regular conditions lead to a restriction of open circuit voltage although the band gap of the i-layer varies widely.A significant improvement in open circuit voltage has been obtained by using high quality p-a-SiC:H films optimized at the "low-power regime" under low silane flow rates and high hydrogen dilution conditions. 相似文献
145.
Yan-Jun Li Peng Wang Jing-Fu Ni Liang Meng Xiao-Bo Wang Chun-Qi Sheng Hong-Nian Li Wen-Hua Zhang Yang Xu Fa-Qiang Xu Jun-Fa Zhu 《Journal of Electron Spectroscopy and Related Phenomena》2011,184(7):414-419
We have measured and analyzed the photoemission spectra (PES) of a C70 film in the photon energy region from 13.4 eV to 98.4 eV. The photoelectron intensities of two C 2p π-derived features (denoted by A and B) oscillate regularly in the whole energy region with some fine structures below ∼30 eV. To obtain the detailed information of the oscillations, we have developed a sophisticated but practical procedure for intensity calculation. The procedure consists of two core concepts. The first is ascribing the PES features to their corresponding molecular orbitals with the help of density functional calculations. The second is a background subtraction algorithm. With this procedure, we obtained the oscillating behavior for individual features (A and B), which is by and large consistent with the predictions based on the spherical symmetric approximation although C70 has the ellipsoidal shape. Owing to the solid state effect, the oscillating amplitudes of the A/B intensity ratios are smaller than those of gas phase C70, but an orbital shift reported recently was not observed on our sample. The oscillating curve of a deeper feature, which consists of both σ and π states, are also reported. 相似文献
146.
This paper investigates the dynamical behaviour of the Liu system with time delayed feedback. Two typical situations are considered and the effect of time-delay parameter on the dynamics of the system is discussed. It is shown that the Liu system with time delayed feedback may exhibit interesting and extremely rich dynamical behaviour. The evolution of the dynamics is shown to be complex with varying time-delay parameter. Moreover, the strange attractor like ‘wormhole' is detected via numerical simulations. 相似文献
147.
由于兰姆波的多模和频散特性,实际检测时在同一激发频率下存在多种模式的混合信号,而各模式信号有不同的频散特性,使得在时频混叠的情况下兰姆波的检测变得十分复杂.本文在频散补偿的基础上,通过时延函数建模,依靠不同模式频散趋势的差异性,将时频混叠信号的分离问题转化为部分模式混叠信号的分离问题.基于分数阶微分的理论,用信号幅值谱分数阶微分极大值和对应频率分别与微分阶次拟合多项式实现特征参数的提取并依靠特征参数重建幅值谱.结合相位谱重构时域信号以实现部分混叠信号中频散补偿后的模式的分离.最后恢复频散获得分离后的兰姆波信号.仿真和实验结果表明,本文方法不仅可以实现时频混叠多模式兰姆波信号的分离,更能保证分离精度,有助于复杂多模式频散信号的分离与处理的进一步研究. 相似文献
148.
Yun Wang Juan Ni Hao Chi Xianmin Zhang Shilie Zheng Xiaofeng Jin 《Optics Communications》2011,284(16-17):3928-3932
A novel photonic technique for instantaneous frequency measurement of microwave signal based on phase modulation to intensity modulation conversion is proposed and demonstrated. In the proposed system, an optical carrier is modulated by a microwave signal with its frequency to be measured through a phase modulator. The phase-modulated optical signal is then converted to intensity-modulated signals in two independent paths using a dispersive media and a frequency discriminator respectively. Since the dependence of the received microwave power on the input microwave frequency in the two paths differs, the microwave power ratio between the two paths can be used to uniquely determine the microwave frequency. The major advantages of the approach lie in that only one laser source and the bias-free phase modulator is employed in the system, which improves the stability of the system. Experimental demonstrations of the frequency measurement based on the proposed approach are presented. 相似文献
149.
为了满足极端紫外波段微通道位敏阳极光子计数探测器研究的需要,研究了碱卤化物光阴极材料的量子效率.由于光阴极材料的光电发射电流主要是由次级电子形成的,给出碱卤化物光阴极材料次级电子发射的理论模型,推导出次级电子产出的计算公式,针对光子能量30—250 eV范围内,计算并分析了光阴极材料厚度和光入射角对次级电子产出的影响.分析结果显示,光阴极材料厚度大于100 nm并且掠入射角大于临界角,是获得高次级电子产出的最佳条件.最后,应用推导的公式分析20种碱卤化物在能量30—250 eV范围内次级电子产出的光谱响应
关键词:
极端紫外
碱卤化物
光阴极
次级电子 相似文献
150.
Transparent GdTaO4:Eu3+ thick films were prepared from the inorganic salt and 2-methoxyethanol solution containing polyvinylpyrrolidone (PVP) via sol-gel technique. The critical thickness of the film, i.e. the maximum thickness achievable without crack formation via non-repetitive deposition, was 0.8 μm. The effect of PVP on the morphology, crystallization behavior and optical property of the GdTaO4:Eu3+ thick film was investigated. The results indicated that PVP could play an important role in the formation of transparent GdTaO4:Eu3+ thick films, suppressing the stress evolution, adjusting the sol viscosity, ameliorating the crystallinity, and strengthening the covalency of Eu-O bonds. The GdTaO4:Eu3+ thick films prepared with PVP exhibited a superior photoluminescence and X-ray exited luminescence, which implies that it will have promising applications in high-spatial-resolution X-ray imaging and flat panel display devices. 相似文献