Enhanced Photoelectrochemical Properties of Zn−Ag−In−Te Nanocrystals with High Energy Photon Excitation

Abstract Multinary nanocrystals (NCs) of I‐III‐VI‐based semiconductors with less toxicity have attracted much attention for the fabrication of efficient light‐energy conversion systems. Here we report unique photoelectrochemical properties of ZnTe−AgInTe₂ solid solution (ZAITe) NCs with a controllable energy gap in near‐IR region. The photoelectrochemical behavior of ZAITe NCs immobilized on an ITO electrode with a thickness of less than one monoparticle layer, resembling a p‐type semiconductor photoresponse, was remarkably different from that of ZAITe NC multilayer films: The onset of a cathodic photocurrent was shifted more positively than that of the valence band maximum of ZAITe NCs and the photocurrent generation efficiency was significantly increased, when photons with energy higher than ca. 2.5 eV were irradiated. These phenomena can be explained well by the direct hot hole transfer from ZAITe NCs to the ITO electrode.