Enhancing effects of reduced graphene oxide on photoluminescence of CsPbBr3 perovskite quantum dots

The composites of CsPbBr3 perovskite quantum dots (PeQDs) and reduced graphene oxide (RGO) nanosheets have been synthesized by an in situ solution reaction. The amount of RGO can significantly affect the photoluminescence of PeQDs. By varying the amount of RGO, the photoluminescence quantum yield can be tuned from 48.4% to 69.3%. PL decay analysis indicates that the radiative decay rate and charge transfer become faster with an increase in the amount of RGO. The ellipsometric data can be described by a double Lorentz oscillator model. The comparison between bare and composite samples indicates that the complex refractive index can be affected by the RGO composite. Numerical simulations on the electric field distribution for PeQD/RGO show that the local electric field around CsPbBr3 QDs is increased by surface plasmon resonance on the surface of the RGO nanosheet. These results suggest that the PeQD/RGO composites can be used for highly efficient light emitting devices.