Doping of 1,1-dicyano-2,2-bis(methylthio)ethylene in ZnO to improve photoresponce of organic solar cells and photodetectors under UV-cut light irradiation

ZnO has been utilized as the electron transport layer in organic optelectronic devices, however, the shortcoming of ZnO is that activation by UV light is essential and ZnO-based optoelectronic devices give poor photoresponse under UV-cut light irradiation. We developed 1,1-dicyano-2,2-bis(methylthio)ethylene (DBE)-doped ZnO which can be activated by visible light irradiation. The DBE-doped organic solar cells showed better photovoltaic performances under UV-cut light irradiation than those of undoped ZnO-based devices and DBE-doped photodetectors also showed better frequency response without applied voltage under monochronic laser irradiation (450 nm) than that of undoped ZnO-based ones.