CHARACTERISTICS OF THE PHOTOCONDUCTIVITY AND OF THE PHOTOMAGNETIC EFFECT IN MNXHG1-XTE CRYSTALS WITH ANODICALLY OXIDIZED SURFACES

An investigation was made of the electrical and photoelectric properties of MnxHg1-xTe (x = 0.09-0.12) crystals as a function of the charge state of an anodic oxide deposited on the surface of a sample. The attention was concentrated on the influence of short-wavelength illumination on the parameters of the surface layers of the semiconductor. A new state of the oxide-semiconductor interface induced at low temperatures (T less than or similar 80 K) by such illumination was retained for a long time and it altered significantly the characteristic features of the photoconductivity and of the photomagnetic effect. The nature of the influence of such short-wavelength illumination on the surface properties of MnxHg1-xTe crystals suggested that the defects responsible for the charge state of the oxide were either amphoteric or were of donor or acceptor types, and their concentrations depended on the composition parameter x of the semiconductor.