Giant switchable photovoltaic effect in organometal trihalide perovskite devices

Organolead trihalide perovskite (OTP) materials are emerging as naturally abundant materials for low-cost, solution-processed and highly effcient solar cells(1-9). Here, we show that, in OTP-based photovoltaic devices with vertical and lateral cell configurations, the photocurrent direction can be switched repeatedly by applying a small electric field of < 1V mu m(-1). The switchable photocurrent, generally observed in devices based on ferroelectric materials, reached 20.1 mAcm(-2) under one sun illumination in OTP devices with a vertical architecture, which is four orders of magnitude larger than lthat measured in other ferroelectric photovoltaic devices(10,11). This field-switchable photovoltaic effect can be explained by the formation of reversible p-i-n structures induced by ion drift in the perovskite layer. The demonstration of switchable OTP photovoltaics and electric-field-manipulated doping paves the way for innovative solar cell designs and for the exploitation of OTP materials in electrically and optically readable memristors and circuits.