Physical properties of AgAs3Se5, Ag2SnAs6Se12 (co-doped with Er3+, Nd3+) single crystals formed in the quasi-ternary system Ag2Se-SnSe2-As2Se3

Phase equilibria of the quasi -ternary system Ag2Se-SnSe2 - As2Se3 were investigated by X-ray phase, differential thermal and microstructural analysis methods. Character of monovariant processes, temperature with coordinates of invariant equilibria were determined. Based on the obtained results the single crystals of AgAs3Se5, Ag2SnAs6Se12 compounds co -doped with Er3+, Nd3+ (AgAs2 & sdot;6Er0.2Nd0.2Se5, Ag2SnAs5 & sdot;6Er0.2Nd0.2Se12) were obtained by the solution -melt method. Studies of photoluminescence spectra in the near-IR range and analysis of the mechanisms responsible for the appearance of photoluminescence bands were carried out. Some electrical, thermoelectric and photoelectric properties of the single crystals AgAs3Se5 and Ag2SnAs6Se12 co -doped with Er3+, Nd3+ were investigated. The type of conductivity was determined by the thermoelectric method, according to the sign of the Seebeck coefficient (alpha). AgAs3Se5 compound has the highest value of alpha = 990 mu V/K, which indicates the promising use of the materials for thermal sensor creation. Ag2SnAs5.6Er0.2Nd0.2Se12 has a photoconductivity change factor of 11 % (T = 300 K).