Structural Data and Luminescence Properties of Cu2 –xMnSnS4 (0 < x ≤ 0.10) Copper-Deficient Solid Solutions Based on the Cu2MnSnS4 Quaternary Compound

— This paper presents the first structural data for Cu 2 – x MnSnS 4 (0 < x ≤ 0.10) copper-deficient solid solutions based on the Cu 2 MnSnS 4 quaternary compound. It has been shown for the first time that the band peaking at 1.26 eV in the 78-K cathodoluminescence spectrum of Cu 2 MnSnS 4 is most likely due to Cu Mn and Mn Cu antisite defects resulting from mutual substitutions of atoms on the copper and manganese sites in the stannite structure and that the spectra of Cu 2 – x MnSnS 4 contain a band peaking at 1.21 eV and arising from Cu 2+ ⋅ V Cu defect associates.