Luminescent and Photoelectric Properties of Hybrid Structures Based on Multilayer Graphene and 0D and 2D Semiconductor Quantum Nanocrystals

Abstract

Determination of regular features of mechanisms underlying interactions of nanostructured materials is one of the most important problems on the way to create the new generation of efficient photovoltaic devices. In this paper, we study the luminescent and photoelectric properties of hybrid structures that are formed on the basis of multilayer graphene nanoribbons and semiconductor quantum nanocrystals of the 0D dimension, CdSe/ZnS core/shell quantum dots, and 2D-dimension CdSe nanoplates. It is shown that the multiexponential decay of the exciton luminescence of CdSe nanoplates at room temperature is determined by the occurrence of delayed luminescence, which is caused by the presence of trap states on the surface of nanoplates. It is found that, in dry layers of nanoplates on a dielectric substrate and in the composition of hybrid structures with graphene nanoribbons, the efficiency of delayed exciton luminescence of nanoplates increases. It is shown that the rate of increase in the photoconductivity in hybrid structures based on CdSe nanoplates is an order of magnitude higher than the rate of this process in similar structures based on CdSe/ZnS quantum dots, which indicates the formation of an effective energy/charge transfer channel from nanoplates to graphene nanoribbons.