Structural and luminescence characteristics of CuAlxIn1−xSe2 (0<x≤0.30) chalcopyrite solid solutions

CuAl_xIn_1−xSe₂ solid solutions with a chalcopyrite crystal structure were synthesized from elemental Cu, In, Al and Se. The dependence of their unit cell parameters on x in a range of 0<x≤0.30 was determined. The band with a maximum at 1.320eV in the cathodoluminescence spectra of CuAl_xIn_1−xSe₂ solid solutions at 78K was most likely due to defects formed upon mutual substitution of atoms between the copper and aluminum–indium sublattices in the chalcopyrite structure.