Excitonic photoluminescence in a CuAlSe2 chalcopyrite semiconductor grown by low-pressure metalorganic chemical-vapor deposition

Abstract
Excitonic photoluminescence (PL) in a CuAlSe2 chalcopyrite semiconductor was observed. High‐quality CuAlSe2 epilayers were grown by the low‐pressure metalorganic chemical‐vapor deposition technique. Based on photoreflectance measurements, the PL peak at 2.739 eV was assigned to a free exciton emission. The PL peak at 2.677 eV was tentatively assigned to a bound exciton emission.