不同响应波长的HgCdTe光导器件噪声分析

研究了不同响应波长的HgCdTe器件在不同背景辐射条件下的噪声变化.随着背景辐射的增加,甚长波器件的噪声减小,而中波器件相反.噪声频谱测量表明,产生-复合噪声分量和1/f噪声分量是器件的主要噪声来源,并且这两个分量随背景的变化趋势相同.非平衡载流子和器件有效寿命的理论分析,表明器件噪声随背景辐射的变化存在一个极大值,而中波和甚长波器件处在不同的作用区域内,接受到的背景辐射对载流子浓度和器件有效寿命的影响不同,从而噪声变化表现不同.在此基础上,提出了"临界背景通量密度"的概念.

Noise Analysis of HgCdTe Photoconductive Detector with Different Response Wavelength

The influence of background radiation on noise of medium-wave and extremely-long-wave HgCdTe detectors is studied. It is found that the noise of extremely-long-wave detector decreases with the background radiation increasing, while for the medium-wave detector is shows the different way. Noise spectra show that the main noise sources are generation-recombination (G-R) noise and 1/f noise which have the similar trend while the background is changing. The G-R noise for different wavelength response detectors is calculated using carriers and effective lifetime theory. There exists a maximum value when G-R noise changes with background radiation. While the noise is on the different position for medium-wave and extremely-long-wave detectors, the influence of background radiation on their effective lifetime is different. So noise behaves differently. Based on these, a new concept of “critical-background-radiation-flux-density” is put forward.