Crystallographic and Luminescence Characteristics of the Cu2MgSnSe4 Quaternary Compound and Cu2 – xMgSnSe4 (0 < x ≤ 0.15) Copper-Deficient Solid Solutions

Abstract

Crystallographic characteristics of the Cu 2 MgSnSe 4 quaternary compound and Cu 2 -x MgSnSe 4 (0 < x ≤ 0.15) copper-deficient solid solutions have been determined for the first time. It has been shown that the band peaking at 1.39 eV in the 78-K cathodoluminescence spectrum of Cu 2 MgSnSe 4 is most likely due to Cu Mg and Mg Cu antisite defects resulting from exchange of atoms between the copper and magnesium sublattices in the kesterite structure and that the spectra of Cu 2 -x MgSnSe 4 contain, in addition to the 1.39-eV band, a band peaking at 1.34 eV, which is due to Cu 2+ • V Cu defect associates.