Low Temperature Studies on the Grain‐Size Effect on the Electro‐optical Properties of ZnO Luminophores

Abstract

The electroluminescence and photoluminescence of the self-activated ZnO luminophores exhibit three prominent bands in the green, yellow and yellow-orange regions. With the reduction in grain size, these bands shift towards lower energy side and their energies are enhanced. The bands shift towards lower energy side with decreasing temperature of the luminophores. Both the electroluminescence and photoluminescence have maximum overall brightness for 33 micron grain size. One additional peak a t 120 O K is found during the brightness studies of electroluminescence and photoluminescence of the luminophores. The appearance of such an additional peak is also confirmed from the studies of the brightness waves. The effects of grain size on the electro-optical properties of the selfactivated ZnO luminophores are discussed on the basis of the existing ideas about photoand electroluminescence.