Diketopyrrolopyrrole Derivatives Functionalized Graphene for High Performance Visible-light Photodetector
Although graphene has unique electronic and optical properties, its application in photodetector is still limited due to the low optical absorption. In this work, we functionalized graphene with diketopyrrolopyrrole derivatives (TDPP, TTDPP) to enhance the light absorption of the hybrid system. A facial in situ solution method was developed for chemical decoration of graphene with diketopyrrolopyrrole derivatives. The morphology, optical absorption and photoluminescence properties were investigated in order to elucidate the interaction between the graphene and diketopyrrolopyrrole derivatives. The time-resolved fluorescence data verified the occurance of the interface charge transfer between TDPP or TTDPP molecules and graphene in the hybrids. The visible-light photodetector based TTDPP/RGO hybrids exhibits a maximum photoresivity of 34.2 A/W and the on/off ratio was 282. We conclude that the high photoresponse is consistent with the efficient charge-transfer process occurred on the interface of TTDPP and graphene. 2D-graphene here serves not only as a superior supporting matrix for anchoring the sensitizer molecules but also as an excellent electron mediator to adjust electron transfer. Our research paves the way to build high-performance optoelectronic devices based 2D graphene and organic compounds.