Growth and cathodoluminescence study of CuAlSe2 single crystals

Single crystals of the optical active CuAlSe2 semiconductor with a diameter up to 18 mm and a length up to 35 mm were grown by the vertical Bridgman method from the elements. The cathodoluminescence (CL) of the as-grown CuAlSe2 crystals was measured at 77 and 300 K. Typical CL spectra consist of some weakly registered bands (1.86, 1.92, 2.05 eV) with various intensity at minimum excitation intensity. The 1.91 eV band at maximum excitation intensity can be considered as the sum of two or more bands with different nature of recombination.