Piezo-phototronic Effect Enhanced Visible and Ultraviolet Photodetection Using a ZnOCdS CoreShell

The piezo-phototronic effect is about the use of the piezoelectric potential created inside some materialsforenhancingthechargecarriergenerationorseparationatthemetalsemiconductor contactorpnjunction.Inthispaper,wedemonstratetheimpactofthepiezo-phototronic effect on the photon sensitivity for a ZnOCdS coreshell micro/nanowire based visible and UV sensor. CdS nanowire arrays were grown on the surface of a ZnO micro/nanowire to form a ZnOCdS coreshell nanostructure by a facile hydrothermal method. With the two ends of a ZnOCdSwire bondedonapolymersubstrate, a flexiblephotodetector wasfabricated,which is sensitive simultaneously to both green light (548 nm) and UV light (372 nm). Furthermore, the performance of the photon sensor is much enhanced by the strain-induced piezopotential in the ZnO core through modulation of the Schottky barrier heights at the source and drain contacts. This work demonstrates a new application of the piezotronic effect in photon detectors.