液相外延HgCdTe薄膜组分均匀性对器件响应光谱的影响

Effect of composition ununiformity of LPE HgCdTe film on response spectral of device

研究了HgCdTe液相外延薄膜的组分均匀性对器件响应光谱的影响。提出了一种计算HgCdTe红外探测器响应光谱的方法,考虑了HgCdTe液相外延薄膜的纵向组分分布和横向组分波动,以及光在器件各层结构中的相干、非相干传输。使用该方法计算了响应光谱的峰值响应率和截止波长随着液相外延HgCdTe的互扩散区厚度△z和组分均方差σ的变化规律。结果表明:对于一般的HgCdTe外延薄膜,σ小于0.002,不需要考虑横向组分波动的影响。同时计算了峰值响应率和黑体响应率随着液相外延HgCdTe的总厚度的变化规律,可以得到最佳的吸收区厚度。

The effect of composition ununiformity of LPE HgCdTe film on spectral response of device was studied. A new method was proposed to calculate the spectral response of HgCdTe IR detector. This method considered longitudinal composition distribution and transverse composition ununiformity in LPE HgCdTe film. The coherent and incoherent light transmission among the device was also included. Using this method, the variation law of peak responsibility of spectral responseand and cutoff wavelength with compositional diffusion width Az and transverse composition deviation tr of LPE HgCdTe film was calculated. The result indicates that for common LPE HgCdTe film, whose o- is less than 0.002, the influence of transverse composition ununiformity on spectral response can be neglected. The changes of peak responsibility and black body responsibility with thickness of LPE HgCdTe film were also calculated. The optimum thickness can be obtained.