White light emission characteristics of two dimensional graphitic carbon nitride and ZnO nanorod hybrid heterojunctions

We report on the white luminescence from heterojunctions based on two dimensional (2D) graphitic carbon nitride (g-C3N4) nanosheets and ZnO nanorods. Nanorods wrapped with nanosheets have been grown using a simple aqueous solution growth method, where the atomistic attachment between g-C3N4 and ZnO leads to the formation of an isotype heterojunction with type-II band alignment. Microscopic studies have indicated the growth of a few layer g-C3N4 using chemical exfoliation. In contrast to the layered structures of g-C3N4 and ZnO, the heterojunction has been found to be efficient to yield the broad emission features. The heterojunction facilitates the violet-blue emission through charge transfer, while the interfacial recombination yields emission in the extreme end of the visible range. The intermixing of individual emission features from g-C3N4 and ZnO along with the interfacial radiative recombination is responsible for the origin of white light emission. The study indicates the potential of 2D/1D heterojunctions to achieve tailored emission characteristics for light emitting applications.