Ga_(1-x)Al_xAs/GaAs光阴极光谱响应向短波延伸的机理分析和实验研究

Mechanism analysis and experiment research of Ga_(1-x)Al_xAs/GaAs photocathode spectral response extending to short wave

为了实现光阴极光谱响应向短波延伸,分析了G a1-xA lxA s/G aA s三代微光光阴极光谱响应向短波延伸的机理,提出了准禁带宽度的概念,讨论了G a1-xA lxA s的禁带宽度随铝组份x值的增加而逐渐变宽的变化规律,计算了不同铝组份下光阴极光谱响应的短波限。通过提高光阴极材料的铝组份,做出了宽光谱响应像管,并给出了相应的光谱响应曲线。通过与标准三代微光像管光谱响应对比,发现:所得光谱响应曲线不仅向短波方向得以延伸,而且理论设计与实验结果吻合很好。

In order the mechanism of wave, is analyzed, to realize the extension of spectral response of photocathode to short wave, Ga1-xAlxAs/GaAs photocathode, whose spectral response extends to short a new concept of Quasi Energy Gap is presented,the rule that the energy gap of Ga1-xAlxAs/GaAs widens gradually with the increase of the aluminum composition x is discussed, and the short-wavelength threshold of spectral response for photocathode in different alLirninum compositions is calculated. Accordingly, the image tube with wide spectral response was made by increasing the aluminum composition of photocathode material, and the corresponding spectral response curve is given. In comparison with the spectral response of the standard Gen. Ⅱ low-level-light image intensifier, the spectral response curve of the tube we made extends to short wavelength. The experimental result coincides with the theoretical demgn.