Pressure‐dependent photoluminescence study of CuGaSe₂

Abstract We present the results of a pressure‐dependent photoluminescence (PL) study on CuGaSe 2 films grown on GaAs substrate by metalorganic vapor phase epitaxy. The low‐temperature PL spectra of the CuGaSe 2 samples measured at atmospheric pressure are dominated by one near band edge exciton luminescence line and two strong and relatively broad emissions associated with donor acceptor pairs (DAP) transitions. All the observed luminescence emission lines shift toward higher energy with increasing pressure at the same rate. The nearly identical pressure coefficients of the two DAP emissions as compared to that of the exciton emission confirm the suggestion that the recombination processes associated with the DAPs involve one shallow effective‐mass donor and two different acceptor species with different binding energies and related to two different native defects. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)