Description:
<jats:p>Photoreflectance (PR) measurements have been performed near the fundamental absorption edge of CuGaS2 single crystals grown by an iodine-transport method. The PR spectra at room temperature are analyzed as the superposition of exciton and band-to-band transition. The exciton transition energies at 290 and 77 K are obtained to be 2.463 and 2.503 eV, respectively. The quality of CuGaS2 crystals grown with different amounts of iodine is characterized with respect to energies and broadening of the PR spectra.</jats:p>