Electric field induced reversible control of visible photoluminescence from ZnO nanoparticles

Reversible control of the photoluminescence of ZnO occurring in the visible range, has been achieved by application of a few volts (<5 V) 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 s, 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. (C) 2011 American Institute of Physics. [doi:10.1063/1.3578194]