Preparation and Characterization of cu(Al, ga)(s, se)2 Penternary Alloys

Abstract

Photoreflectance (PR) and Photoluminescence (PL) measurements have been performed at 77 K on single crystals of CuAlxGa1_JC(So.5Se0.5)2 penternary alloys grown by the iodine chemical vapor transport method. The energies of excitonsassociated with uppermost valence bands have been obtained as a function of composition, and an approximately quadratic dependence has been found. Near-band-edge PL has been observed in the crystal with x^ 0.77, and the PL has beendiscussed in terms of the free exciton. © 1993 The Japan Society of Applied Physics.