Transparent and flexible ultraviolet photoconductors based on solution-processed graphene quantum dots on reduced graphene oxide films

A combination of graphene quantum dots and chemically reduced graphene oxide films was obtained by spray-coating their dispersions onto an indium tin oxide coated polyethylene terephthalate substrate. Herein, the graphene quantum dots played a major role in the absorption of ultraviolet light and generation of carriers, whereas the reduced graphene films acted as the transparent electron pathway network. Consequently, the fabricated structure showed good transparency and flexibility, and achieved noticeable ultraviolet sensing. The facile, inexpensive, and extremely low temperature techniques used can be easily upgraded to a larger scale and are compatible with other substrates. In addition, a combination of reduced graphene oxide and graphene quantum dots offers a potential graphene-based platform for foldable optoelectronic device applications.