The CdAl2S4 single crystal grown by the chemical transport reaction me
thod in an excess sulfur atmosphere showed the intensive blue photolum
inescence (PL) peaked at 462 nm at 280 K. The CdAl2S4 single crystal h
ad the defect chalcopyrite structure, and the optical energy gap of th
e single crystal with the direct band structure was found to be 3.398
eV at 280 K, and to be 3.577 eV at 17 K. (C) 1997 American Institute o
f Physics.