LPE GaAs/(Ga, Al)As/GaAs transmission photocathodes and a simplified formula for transmission quantum yield
LPE GaAs/(Ga, Al)As/GaAs transmission photocathodes and a simplified formula for transmission quantum yield
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DOI：
10.1063/1.1662208
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发表时间：
1973-12
影响因子：
3.2
通讯作者：
Y. Z. Liu;C. D. Hollish;W. Stein;D. Bolger;P. Greene
中科院分区：
文献类型：
--
作者：
Y. Z. Liu;C. D. Hollish;W. Stein;D. Bolger;P. Greene
采用多层液体外延技术，在GaAs衬底上制备了GaAs/(Ga，Al)As/GaAs透射型光电阴极。随后，通过气泡刻蚀去除了GaAs衬底。通常可以获得340μA/lm的传输模式白光灵敏度和5μm或更长的电子扩散长度。发现其反射灵敏度低于直接生长在GaAs衬底上的类似薄膜。当用屈服公式分析光谱响应时，表明在GaAs/(Ga，Al)As界面上的复合可以忽略不计。此外，尽管GaAs和AlAs之间的晶格匹配几乎是完美的，但观察到了一些弯曲现象，这表明存在内应力。导出了传输量子产额的简化公式，使光阴极输入面的表面复合速度和光阴极厚度与电子扩散长度之比的图解不需要繁琐的计算机计算。
GaAs/(Ga,Al)As/GaAs transmission photocathodes were fabricated by a multiple layer liquid epitaxy technique using GaAs substrates. The GaAs substrate was subsequently removed by bubble etching. Transmission mode white light sensitivity of 340 μA/lm and an electron diffusion length of 5 μm or more can be routinely achieved. The reflection sensitivity was found to be lower than that of a similarly prepared layer grown directly on the GaAs substrate. The spectral response, when analyzed with the yield formula, indicated negligible recombination at the GaAs / (Ga,Al)As interface. Also, despite the almost perfect lattice match between GaAs and AlAs, some bowing of the GaAs / (Ga,Al)As samples was observed, suggesting the presence of internal stresses. A simplified formula is derived for the transmission quantum yield which enables graphic solution of surface recombination velocity at the photocathode input surface and the ratio of photocathode thickness to the electron diffusion length without tedious computer calculations.