57Fe and 119Sn Mössbauer spectroscopy of the CuAlS 2 chalcopyrite semiconductor

Abstract

57Fe and 119Sn Mössbauer spectroscopy of the CuAlS 2 chalcopyrite semiconductor has been carried out at the room temperature. The values of the isomeric shift (IS) and quadrupolar splitting (QS) are determined. It is established that at doping of the CuAlS 2 compound by replacement of 2 at% of aluminium atoms of iron are as in three-valent state, occupying structural positions of atoms of aluminium and in two-valent one. The change in the charging condition of atoms of iron is caused by the kinetics of formation of ternary compounds from the constituent elements, occupation by iron atoms of structural positions of copper, influence (shielding) of acceptor impurities. Atoms of tin on doping of the CuAlS 2 and CuGaS 2 compounds cause replacement of 2 at% of sulphur and are included into sites of anion's sub-lattice, they are in two-valent state and the value of IS is determined by their local state.