Optical modulation of hole doping via atomically thin fluorine-functionalized graphene endowed transparent and flexible UV-photodetector

Abstract

Understanding the charge-formation dynamics and current flow of consecutive carbon quantum dot (CQD) layers biased by atomically thin fluorine-functionalized graphene (FF-Gra) as light-driven modulators is manifested. By probing the involved electronic structures and optical transitions, we reveal that the trion population and dynamic phenomena, rather than intuitive photogenerated electron-hole pairs, exhibit as main features of CQD/FF-Gra heterostructures for the modulation of photophysical origin, where the anomalous pathway for coupling out trion state with faster growth configuration than intrinsic exciton-to-trion transition is interpreted by the extrinsic hole doping coupled with exitonic bound states. All these features implicate the outstanding UV-responsive flexible photodetectors with sound optical transparency, attesting external quantum efficiency (EQE) of 1.68x109%, photoresponsivity of 4.66x106 A/W and detectivity of 2.92x1018 Jones based on such nonintuitive quantum-confined hybrid materials.