Photo and electroluminescence of ZnO : Er and ZnO : Ag,Er electroluminors

A number of ZnO : Er and ZnO : Ag, Er electroluminors have been prepared and their photo (PL) and electroluminescent (EL) properties investigated. While the addition of Ag slightly shifts the PL spectra towards longer wavelength side, the EL spectra not only shift but consist of some new transitions. In ZnO : Er electroluminors, additional transitions also exist at higher frequencies of excitations. Brightness waves for this system consist of two secondary peaks during each half cycle of exciting field. Temperature dependence shows two broad peaks. While voltage dependence of ZnO : Er satisfies the relationB=B ₀ exp(−b/V ^1/2), the relationB=B ₀ V exp(−b/V ^1/2) is found to be suitable for ZnO : Ag, Er electroluminor. Possible mechanisms for these phenomena have been proposed. A preliminary account of this work was presented at the International Symposium on Solid State Physics held at the Indian Association for the Cultivation of Science, Calcutta in January 1977.