PHOTOELECTRIC PROPERTIES OF POLYCRYSTALLINE CDXHG1-XTE FILMS GROWN ONALTERNATIVE SUBSTRATES

The photoelectric and electrical properties and structure of polycryst alline CdxHg1-xTe films grown on Al2O3 (x = 0.28) and GaAs (x = 0.80) substrates are studied. The films obtained, having a high photosensiti vity in particular at room temperature, show promise for infrared opto electronics. A comprehensive investigation of the photoconductivity sp ectra, lux-ampere characteristics and temperature dependences of the p hotoelectric and electrical characteristics have established the signi ficant influence of electrically active grain boundaries on the photoe lectric parameters. It has been found that lux-ampere characteristics of CdxHg1-xTe/GaAs films have a nonconventional pattern which is manif ested in an increase of slope at high rates of laser excitation. The r ole of potential barriers in the generation-recombination processes in polycrystalline films is discussed in the context of a model of an in homogeneous semiconductor whose energy bands are modulated by a random potential.