Photoresistors from heteroepitaxial structures n-CdxHg1-xTe with exclusion of charge carriers within the 3–5 µm spectral range

Abstract

The properties of photoresistors with photosensitive areas of 0.05mm×0.05mm and 0.5mm×0.5mm made of heteroepitaxial structures n-CdxHg1−xTe were investigated within the spectral range of 3–5 µm using indium contacts at a temperature of 80 K. The dependence of the lifetime and concentration of the charge carriers inside the pixels on the bias voltage was determined within a wide range of exposure to background radiation. In photoresistors with a pixel size of 0.05mm×0.05mm, a nonequilibrium mode of operation with the exclusion of minority charge carriers can be realized. The electron concentration in this mode decreases to 1×1013cm−3. Photoresistors made of epitaxial structures n-CdxHg1−xTe (x≈0.305) in exclusion mode at 80 K have a voltage sensitivity of the order of 107V/W and a specific detectivity of approximately 1.3×1012cm⋅Hz1/2/W.