Injection current and infrared photosensitivity in isotype p-PbTe/p-CdTe heterojunctions

Iso-type p-PbTe/p-CdTe heterojunctions were grown on BaF2 substrates by using the hot-wall epitaxy technique. The growth details are presented. The carrier transport mechanism was investigated by means of the current-voltage measurements. At 77 K the dominant conduction mechanism was found to be the space-charge-limited current. The photovoltaic response in the long-wave infrared region with the half-peak cut-off wavelength ranged from 8.0 to 9.0 m was observed in these heterojunctions for the first time. The possible mechanism of the photoresponse is the internal photoemission of holes from p-PbTe across the heterojunction barrier.