Photoconductivity of Cd1-xZnxSe films in IR region deposited from solution

A. Sh. Abdinov, M. A. Jafarov, R. F. Babayeva, E. F. Nasirov, H. M. Mamedov
Baku State University, Azerbaijan

The Cd1-xZnxSe films, deposited from solution, differ by high photosensitivity in visible and near IR region of spectrum. In present paper are called the results of induced impurity photoconductivity (IIP) of Cd1-xZnxSe (0 <= х <= 0,5) films in region of 2,5—3,0 mm. The Cd1-xZnxSe films are obtained on glass-ceramic substrates by chemical deposition from aqueous solution, containing cadmium and zinc salts, and thiourea. The films are subjected to heat-treatment in air at temperatures 400—500 °C for 0—30 min. A quasi-linear spectrum of IIP adjoins to band according to impurity band from the side of high energy. At the spectrum of IIP have been observed narrow bands, the half-wide is 0,03—0,04 eV. With increasing the levels of primary photoexcitation the "deformation" of IIP spectrum to region of high energy, which appears in bands spectrum maximum. The value of "violet" shear is equal to D E = 0,05 eV. The values of these phenomena are determined by nature of multilevels associate, which are related to the optical activated sticking centers of electrons. At the same time the intensity of wide IIP band (hv0 = 0,3 eV), in a low-temperature region) weak dependences on temperature, on which testily band-impurity character of ionization of according ionizated donor centers. The isolated donors characterized by level of Ec = 0,29—0,32 eV and cross-section of capture (Sn = (2—4)·10–17 m2). Their participation in called associates provides appearance of systems of optical active electron states, entered in energy range of 0,3—0,6 eV, having conditioned by high-temperature stable photosensitivity of Cd1-xZnxSe films in IR-region. It is shown that, the studied Cd1-xZnxSe films could be in use as a ordinary and cheep elements of memory of optical records, transformers of visible light to IR radiation.

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