The functioning of photoresistors made from constant-composition n-CdxHg1−xTe (x=0.187–0.215) heteroepitaxial structures with variband layers obtained by molecular-beam epitaxy is studied in the nonequilibrium minority-carrier exclusion regime in a wide range of background radiation. The bias-voltage dependences of the electron concentration and charge-carrier lifetime in a 50×50 μm photoresistor pixel are determined at liquid-nitrogen temperature. It is established that the electron concentration in the exclusion regime decreases to a value close to the intrinsic charge-carrier concentration. A voltage sensitivity of more than 2.4×107 V/W and a specific detectivity of 5.3×1011 cm Hz1/2/W are obtained at 77 K and a planar viewing angle of 14° in the exclusion regime for photoresistors made from x=0.203 structures. It is shown that it is promising to use the minority-carrier exclusion regime to create high-efficiency fast-response photoresistors in the 16–17-μm spectral range, cooled no lower than liquid-nitrogen temperature.
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