Compensation in heavily N-doped ZnSe: A luminescence study

Heavily doped ZnSe:N samples were studied using photoluminescence and excitation spectroscopy. The luminescence was found to depend sensitively on the sample temperature and the excitation. The results are attributed to fluctuations in the band and impurity levels which result, via charged ions, from compensation. The quenching of the luminescence led to a measured activation energy of about 40 meV, presumably caused by the thermalisation of carriers from the deep donor states. The excitation spectrum of the luminescence peak shows excitation well below the band-gap, consistent with the proposed model.