Low-temperature photoluminescence study on Er-doped GaP grown by organometallic vapor phase epitaxy

Low-temperature photoluminescence spectra of Er-doped GaP grown by low-pressure organometallic vapor phase epitaxy was investigated under both above-band gap and below-band gap excitation conditions. Under all experimental conditions, similar Er-related spectra dominated by numerous sharp emission lines were obtained for the first time. The intensity dependence of the photoluminescence exhibits complicated behavior and is modeled using a unique energy-transfer process. The results obtained indicate that some Er-related luminescence centers are efficiently activated by direct excitation of electrons to some traps related to the luminescence centers.