Methylammonium lead iodide perovskite-graphene hybrid channels in flexible broadband phototransistors

A flexible photodetector based on methylammonium lead iodide perovskite-graphene (Gr) hybrid channel field-effect transistors (FETs) are studied under broadband incident light and at various photon intensities (515 nm). The combination of high light absorption of the antenna material (perovskite) and excellent mobility and conduction of the transport layer (Gr) in the hybrid channel enables the photodetector to reach high responsivities (up to 115 A W−1) at 515 nm. The change in transfer characteristics of the hybrid channel phototransistor under light exposure allows for a deep understanding of the sensing mechanism and carrier transport properties of Gr based on the shifting of Dirac points (VDirac). Additionally, the as-fabricated device on polyimide substrates yields good mechanical flexibility, electrical stability, and endurance with the responsivity being unaffected under flexure and the photocurrent being unchanged after 3000 bending cycles at a 12 mm bending radius. This work demonstrates the promising potential of these materials for future application in next generation optoelectronic devices.