With the use of CuAl1-xGaxSe2 (x = 0.0, 0.2, 0.5, 0.7, and 1.0) ingots
as starting materials, CuAl1-xGaxSe2 single crystals were grown by th
e chemical transport reaction method using iodine as a transport agent
. Photoluminescence (PL) spectra, PL-excitation spectra, and thermally
stimulated current (TSC) spectra were measured. The PL mechanism was
identified on the basis of the deep levels deduced from the TSC spectr
a in the CuAl1-xGaxSe2 single crystals.