Piezo-phototronic Effect for Enhanced Sensitivity and Response Range of ZnO Thin Film Flexible UV Photodetectors

In this work, we fabricated a ZnO thin film flexible UV photodetector with a room-temperature process and investigated it with an emphasis on the influence of different external stresses. The photodetector exhibited enhancing photocurrent, sensitivity, responsivity, and response range with a tensile strain. This may originate from the improving collection ability of photogenerated carriers with the change of Schottky barrier height, which is induced by the piezo-phototronic effect. The as-obtained thin film flexible photodetector belongs to the family of photoresponse-controlled optoelectronic devices and has applications in a myriad of useful ways.