碲镉汞探测器在高温目标下的光电倍增效应

针对不同波段的碲镉汞红外探测器在探测高温目标情况下的特性进行了研究。测量结果显示随着所探测目标温度的不断升高，器件光生电流亦随之上升，但并非平行变化，这就导致了探测器动态微分阻抗不断下降。器件微分电阻下降的主要原因是p?蛳n结由于背景辐照和反向偏压的增加，引起光生载流子的激增，碰撞电离导致的光电倍增效应引起的，这种效应使得器件光生电流并非是单纯叠加在器件反偏暗电流之上、只随辐射通量而变化的变量，同时也是偏压的函数，随着偏压的增大会对微分阻抗有一个降低作用。通过理论计算这种假设得到了证实，实验结果和理论计算吻合的比较好。

Effects of photocurrent multiplication in HgCdTe photodiodes at high temperature target

The characteristic of different wave-band HgCdTe photodiodes has been investigated when detecting high temperature target .Experimental result shows the photocurrent-generated increases as the temperature of target rises. But this change isn′t parallel. Therefore,it results in the decrease of dynamic differential resistance little by little. Drop of differential resistance results from the effect of photocurrent multiplication,which is due to the electron impact ionization when photocurrent-generation proliferates. This effect makes the differential resistance of photodiode is not constant and it will decrease when the converse bias voltage ascends. The above results have been approved by the calculation of theory and the calculated results agree with the measured results.