Electron transfer governed by light–matter interaction at metal–semiconductor interface

The photoexcitation of heterostructures consisting of metallic nanoclusters and a semiconductor has been extensively investigated in relation to interests in photocatalysis and optical devices. The optoelectronic functions of the heterostructures originate from localized surface plasmon resonance, which can induce electron and resonance energy transfers. While it is well known that photoinduced electronic interaction between a metallic nanocluster and a semiconductor is responsible for the resonance energy transfer, the electron transfer associated with the photoinduced electronic interaction has not been discussed. In this paper, we elucidate the photoexcitation dynamics of a silver nanocluster/TiO 2 heterostructure using an original first-principles computational approach that explicitly deals with light–matter interactions. It is shown that the photoinduced silver–TiO 2 electronic interaction causes excited electrons to be directly transferred from the silver nanocluster to the TiO 2 layer without passing through the conduction band of the silver nanocluster.