Highly photosensitive CsPbBr[formula omitted] NCs-graphene phototransistor with memory function

Abstract

A high-performance Violet-light phototransistor with memory function was fabricated using CsPbBr3 nanocrystals as light absorption material, graphene as fast charge transfer channel, and graphene oxide as charge storage medium. The device demonstrated a responsivity of 2 × 103 A/W and a detectivity of 2.3 × 1012 Jones under illumination of a 405 nm laser. Moreover, the phototransistor showed an excellent photoswitching stability and a high response speed with the rise/decay times of 93/31 ms, respectively. The photoresponse mechanism was discussed using a charge injection model in an energy band diagram of CsPbBr 3 NCs and graphene interface. In addition, the device exhibited charge storage capabilities with a memory window of about 0.4 V attributed to graphene oxide as trapping layer. This work provides a viable route to fabricate phototransistors with storage capabilities.