Temperature dependence of photoluminescence properties in InP/ZnS core-shell quantum dots

Abstract

The photoluminescence properties of InP/ZnS core-shell quantum dots with four kinds of different sizes were investigated under temperature from 80 K to 300 K by the excitation of 405 nm continuous light. The photoluminescence peak was red-shift with temperature increasing which mechanism was attributed to the interaction of excitons and longitudinal acoustic phonons, and the longitudinal acoustic phonon energy 22 meV was obtained. The linewidth of photoluminescence was broadened with temperature increasing which came from the contribution of both the exciton-longitudinal acoustic and exciton-optical phonon interaction, and the longitudinal optical phonon energy 41 meV was obtained as well. The intensity of photoluminescence was decreased with temperature increasing which were attributed to two energy loss processes. One was the interaction of excitons and longitudinal acoustic phonons, and the other was the interaction of excitons and multiple longitudinal optical phonons. The relationships of photoluminescence peak, linewidth, and intensity with particle sizes of InP/ZnS quantum dots were discussed simply as well.