Graphene/nitrogen-functionalized graphene quantum dot hybrid broadband photodetectors with a buffer layer of boron nitride nanosheets

Abstract

A high performance hybrid broadband photodetector with graphene/nitrogen-functionalized graphene quantum dots (NGQDs@GFET) is developed using boron nitride nanosheets (BN-NSs) as a buffer layer to facilitate the separation and transport of photoexcited carriers from the NGQD absorber. The NGQDs@GFET photodetector with the buffer layer of BN-NSs exhibits enhanced photoresponsivity and detectivity in the deep ultraviolet region of ca. 2.3 × 10⁶ A W⁻¹ and ca. 5.5 × 10¹³ Jones without the application of a backgate voltage. The high level of photoresponsivity persists into the near-infrared region (ca. 3.4 × 10² A W⁻¹ and 8.0 × 10⁹ Jones). In addition, application in flexible photodetectors is demonstrated by the construction of a structure on a polyethylene terephthalate (PET) substrate. We further show the feasibility of using our flexible photodetectors towards the practical application of infrared photoreflectors. Together with the potential application of flexible photodetectors and infrared photoreflectors, the proposed hybrid photodetectors have potential for use in future graphene-based optoelectronic devices.