Luminescence of cadmium and zinc phosphides

Stimulated emission was obtained from tellurium-doped Cd$_3$P$_2$ single crystals in the temperature range 10–150$^\circ$ K. The properties of the stimulated radiation were investigated. This radiation grew out of a spontaneous cathodoluminescence band at $\lambda_{\max}=2.12\mu$ at 90$^\circ$ K and the threshold electron current density was $\lesssim50.5$ A/cm$^2$. Cathodoluminescence of Zn$_3$P$_2$ was investigated for the first time and the results were used to find more accurately the forbidden band width of this material. The cathodoluminescence of cadmium and zinc phosphides was located in the region of the fundamental absorption edge and the position of the cathodoluminescence maximum was practically independent of temperature.