Electron accumulation in graphene by interaction with optically excited quantum dots

Zero-dimensional semiconductor nanocrystals (quantum dots) are known to interact with other metallic or semiconductor medium by means of resonant energy transfer or transfer of electronic charge. In the present work we demonstrate efficient electronic interaction of quantum dots and recently discovered graphene, single atom thick two-dimensional carbon crystal. Transfer of optically generated carriers from a quantum dot to graphene is seen by the quench of quantum dots photoluminescence and confirmed by the electrical measurements on single-layer graphene transistor. The phenomenon reported could find an application in graphene-based optical switching and light harvesting.

Research highlights
► Photoluminescence of quantum dots is suppressed when they are deposited on graphene.
► Charge transfer from optically excited quantum dots to graphene is demonstrated.
► We propose the use of graphene as a scaffold for efficient light harvesting devices.