SYNTHESIS, STRUCTURE AND OPTICAL PROPERTIES OF Cd1-xMnxTe POLYCRYSTALS AND THIN FILMS

Abstract

The results of the study of structural properties, surface morphology, and optical parameters of Cd1-xMnxTe solid state
solutions with manganese concentrations x= 0.05 and 0.45 are presented. The synthesis of polycrystalline samples was carried
out by the method of directed crystallization of the melt (vertical Bridgman method). Cd1-xMnxTe solid state solutions were
crystallized in the zinc blende structure (structure type – ZnS, space group F-43m (No. 216)). Concentration ratios of the
components were investigated by the methods of X-ray diffraction and energy-dispersive analysis. The elemental distribution
on a fresh chip of a Cd1-xMnxTe solid solution was studied. The synthesized polycrystalline samples were used as a charge for
the deposition of Cd1-xMnxTe thin films by the closed space sublimation method. For both charges, with a manganese content
of х= 0.05 and 0.45, thin films similar in composition were obtained. On the basis of energy-dispersive analysis, it was found
that the Mn content is ~ 0.03 (at the initial charge, with a manganese content of x= 0.05). The change in composition can be
caused by the imbalance of the film deposition process. The optical transmission spectra (700–1000 nm) showed that the
Cd0.97Mn0.03Te thin film is characterized by an optical band gap of ~ 1.45 eV. Also, the value of the refractive index was
calculated based on empirical ratios.