Photoluminescence properties of nitrogen-doped ZnSe grown by molecular-beam epitaxy

Abstract
This letter reports the photoluminescence (PL) properties of N‐doped ZnSe epilayers grown by molecular‐beam epitaxy using a microwave plasma source for N doping. The temperature dependence of PL spectra from N‐doped ZnSe epilayers with different net acceptor concentrations is described in detail. The emission due to transition from deep donors to free holes (DdF) is observed from highly N‐doped ZnSe epilayers at high temperatures, which gives a direct evidence for the formation of a deep N‐associated donor. The ionization energy for a deep N‐associated donor is estimated as 55±5 meV from comparison of the temperature dependence of the DdF emission energy with that of the free exciton energy.