Direct and Indirect Interfacial Electron Transfer at a Plasmonic p-Cu7S4/CdS Heterojunction

Plasmonic semiconductors exhibit significant potential for harvesting near-IR solar energy, although their mechanisms of plasmon-induced hot electron transfer (HET) are poorly understood. We report a transient absorption study of plasmon-induced HET in p-Cu7S4/CdS type II heterojunctions. Near-IR excitation of the p-Cu7S4 plasmon band at ∼1400 nm leads to ultrafast HET into the CdS conduction band with a time constant of