Photoluminescence of nitrogen-doped zinc selenide epilayers

Photoluminescence (PL) studies or nitrogen doped ZnSe epilayers grown by molecular beam epitaxy have been performed as a function of excitation wavelength, power density, and temperature. The broad emission fi om heavily doped ZnSe:N is composed of two distinct bands which we label as N-I and N-II. The dominant band N-I appears at 2.54 eV, while the N-II band position is sensitive to excitation power and occurs between 2.55 and 2.61 eV. The N-I emission energy is insensitive to incident power or temperature over the ranges studied. Further, a 69 meV localized phonon csf the N-I band is observed, We propose that the N-I band is related to transitions within a (V-Se(+)-Zn-N-Se(-))(0) close-associate pair. The N-II band displays characteristics consistent with the conventional donor acceptor,pair model. A third band N-III, at 2,65 eV is observed under high-power pulsed excitation. Previous studies of heavily doped ZnSe:N had suggested that the broad emission hand was described by a modified donor-acceptor pair model, Our PL study does not support this previous model. In addition, our data suggests that singly ionized selenium vacancy complexes form in heavily doped ZnSe:N and play a role in compensation.