The g-factor of CuGaSe₂ studied by circularly polarised magneto-reflectance

Abstract

High structural quality single crystals of CuGaSe2 were studied using photoluminescence (PL), optical reflectivity (OR) and circularly polarised magneto-reflectance (MR) at 4.2 K in magnetic fields B up to 14 T. At B = 0 T both the PL and OR spectra exhibited the A free exciton, associated with the uppermost sub-band of the valence band of CuGaSe2 split by the tetragonal distortion in the lattice. The magnetic field induced a blue shift of the exciton in the MR spectra. Analysis of the dependence of the spectral position of the A exciton on B in the MR spectra, measured for both right and left circular polarisations of light, enabled the magnitude of its effective g-factor to be determined |g| = 0.46.