Magnetic and Electric Field Dependent Charge Transfer in Perovskite/Graphene Field Effect Transistors

Stable all-inorganic CsPbX3 perovskite nanocrystals (PNCs) with high optical yield can be used in combination with graphene as photon sensors with high responsivity (up to 10(6) A W-1) in the VIS-UV range. The performance of these perovskite/graphene field effect transistors (FET) is mediated by charge transfer processes at the perovskite - graphene interface. Here, the effects of high electric (up to 3000 kV cm(-1)) and magnetic (up to 60 T) fields applied perpendicular to the graphene plane on the charge transfer are reported. The authors demonstrate electric- and magnetic-field dependent charge transfer and a slow (>100 s) charge dynamics. Magneto-transport experiments in constant (approximate to 0.005 T s(-1)) and pulsed (approximate to 1000 T s(-1)) magnetic fields reveal pronounced hysteresis effects in the transfer characteristics of the FET. A magnetic time is used to explain and model differences in device behavior under fast (pulsed) and slowly (continuous) changing magnetic fields. The understanding of the dynamics of the charge transfer in perovskite/graphene heterostructures developed here is relevant for exploitation of these hybrid systems in electronics and optoelectronics, including ultrasensitive photon detectors and FETs for metrology.