Electric field induced reversible control of visible photoluminescence from ZnO nanoparticles

TL;DR

This study demonstrates reversible, voltage-controlled modulation of visible photoluminescence in ZnO nanoparticles using a solid polymer electrolyte, with rapid response and potential for optoelectronic applications.

Contribution

It introduces a novel method to reversibly control ZnO photoluminescence via electric fields using a polymer electrolyte device.

Findings

Nearly 100% modulation of PL intensity

Response time less than 30 seconds

Effect explained by defect states and band bending

Abstract

Reversible control of the photoluminescence of ZnO occurring in the visible range, has been achieved by application of a few volts (< 5V) to a device consisting of nanostructured ZnO film sandwiched between Indium Tin Oxide electrode and polyethylene oxide-lithium perchlorate, a solid polymer electrolyte. The photoluminescence intensity shows nearly 100% modulation with a response time less than 30 seconds, when the bias is applied at the electrolyte-electrode. A model is proposed for the observed effect that is based on defect states of ZnO and the band bending at the ZnO-electrolyte interface that can be changed by the applied bias.