Compensating defects in heavily nitrogen-doped zinc selenide: A photoluminescence study

Photoluminescence (PL) from a heavily nitrogen-doped ZnSe epilayer grown by molecular beam epitaxy was studied as a function of excitation wavelength, power density, and temperature. Also, the time decay of the PL emission was measured. Detailed analysis of the PL data indicates that the deep broad emission is composed of three distinct recombination processes, two are dominant at low power and a third can be detected at higher excitation power. These three bands are labeled NI, NII, and NIII with corresponding peak energies at 2.54, ∼2.58, and 2.65 eV. The NI band is accompanied by phonon replicas of energy 69±3 meV. The behaviors of the NI, NII, and NIII bands are consistent with intracenter recombination, donor–acceptor pair recombination, and electron–acceptor recombination, respectively.