High-Performance Photodetector Based on a Graphene Quantum Dot/CH₃NH₃PbI₃ Perovskite Hybrid

Organometallic perovskites have great potential for their utilization in photodetectors. However, the photoresponsivity of the perovskite film is limited by the low light absorption and charge transport capability. The preparation of good quality film with higher light-harvesting capability on the substrate has been a challenging job until now. In this work, we have developed high-quality white fluorescence graphene quantum dots and a CH3NH3PbI3 hybrid film by a one-step solvent-induced fast deposition–crystallization technique for the photodetector applications. Various amounts of graphene quantum dots are added in composites to optimize the device performance, and the hybrid film results in smooth and compactly distributed crystalline grains. The hybrid film device has exhibited 2 times higher photocurrent-to-dark current ratio, three-fold improved responsivity of 12 A W–1, detectivity enhancement up to 6.5 × 1011 Jones, and a faster response speed compared to that of the neat MAPbI3 at −3 V bias voltage. The graphene quantum dot addition induces efficient charge transfer and enhances the photocurrent by more than 2 times compared to the neat film. High light absorption and fast charge transport capability of the film are primarily responsible for the high performance of the photodetector.