Facile Fabrication of Flexible Photosensors Using Zinc Oxide Tetrapods and Their Ultraviolet Response Evaluation

Abstract

ZnO is a direct semiconductor with excellent ultraviolet (UV) sensing ability due to its wide band gap and high exciton binding energy. Chemical and thermal stabilities of the material also make it a good candidate for applications in various electronic and optical fields. Here, we report the synthesis of ZnO tetrapods using an atmospheric pressure microwave plasma jet system and successive facile fabrication of flexible photosensing devices. The synthesized ZnO tetrapods show high crystallinity and are dispersed in deionized water by brief sonication. The ZnO suspension can then be simply spray-coated on polymeric polyimide (PI) films. To evaluate photosensing characteristics of the devices, devices were intermittently exposed UV light and the corresponding photocurrent was measured. A highly stable and reliable photosensing ability was confirmed. We believe that the ZnO-based PI films prepared by simple spray coating can be applied as flexible photosensors.