Charge transfer and energy transfer in CsPbBr₃-Au nanocrystals based binary nanoheterostructures

Binary nanoheterostructures are interesting direction of heterostructure field because of the diversity of constituent components, novelty of generated properties and cooperativity among long range ordered nanoheterostructures. Carrier behaviors in nanoheterostructures determine their photoelectron properties and strongly dependent on the interfacial effect between constituent components. In this paper, CsPbBr₃-Au nanoheterostructures are constructed by self-assembling of cubic CsPbBr₃ nanocrystals and spherical Au nanocrystals. Transient state observations suggest that energy transfer process enhanced by both interband transition and surface plasmon resonance. For small sized Au nanocrystals, charge transfer process also can be observed since the delocalization of electrons has less change in CsPbBr₃ nanocrystals combined with small sized Au nanocrystals. In addition, carrier interactions are enhanced in small sized Au nanocrystals and carrier scattering rate is accelerated, so the carrier generation and relaxation process of Au nanocrystals and CsPbBr₃-Au nanoheterostructures accelerates as the size of Au nanocrystals decreases. These findings are helpful to understand photoelectron behavior on the interface of nanoheterostructures within nanometer scale and thus optimizing of nanoheterostructure materials.