The chalcopyrite CuAlS2 compound was grown from stoichiometric melt by
horizontal Bridgman method. The obtained ingots were crushed finely and
annealed at different temperatures from 800 °C to 1100 °C under a gas
mixture of 5% N2/H2 atmosphere. X-ray diffraction and Raman
spectroscopy were used to investigate the layer microstructures, as well as
their lattice vibration spectra. The layers were characterized by scanning
electron microscopy (SEM) and the compositional analyses were done by energy
dispersive X-ray microanalysis (EDX). Raman measurements of the as made
powder indicated seven prominent peaks at 205, 250, 290, 340, 369, 418 and
457 cm−1 with large intensity at 457 cm−1. The peaks at 205, 250,
340 and 457 cm−1 were ascribed to B2 modes while the peaks 369 and
418 cm−1 were ascribed to E modes. The peak at 290 cm−1 may be
assigned to the A1 mode. After annealing, the Raman features become
better and phonon mode at 290 cm−1 looks more distinct. The
stoichiometric CuAlS2 compound was obtained when the sample was
annealed at 900 °C.