Photoluminescence of ZnSe single crystals diffused with a group-III element

Abstract

Photoluminescence of ZnSe single crystals doped with group‐III elements (Al, Ga, In) has been studied in order to obtain both a high blue luminescence quality and suitable conductance for making a luminescence diode. The highest‐energy blue emission, which is the strong blue emission in electroluminescence at room temperature, is increased with Zn‐Ga diffusion. The free‐to‐bound blue emission is enhanced and the self‐activated orange emission is suppressed with Zn‐Ga and Zn‐In diffusion. The Zn‐Al and Ga diffused crystals exhibit only the self‐activated emission. Several characteristics of the recombination centers have been examined, including the temperature dependence of the emission peak energy, half‐width, and emission intensity, as well as excitation spectra for these centers. Information gained from these studies concerning impurity levels and luminescence processes in impurity‐doped ZnSe crystals is discussed.