Ultrafast Electron Transfer Dynamics in CdSe/CdTe Donor−Acceptor Nanorods

Abstract

Photoinduced charge transfer dynamics in type-II CdSe/CdTe donor−acceptor nanorods were studied in real-time using femtosecond broadband pump−probe spectroscopy. Following photoexcitation of CdTe (λex = 620 nm), spectral bleaching from the state-filling signals of the band-edge optical transitions was measured using a femtosecond white light pulse (λprobe = 350−750 nm). Excitation of the lowest energy CdTe transition shows an ultrafast change in the bleaching signals of both the CdTe and CdSe lowest energy 1S transitions as well as the characteristic carrier transfer band. Our results indicate that interfacial interconduction band electron transfer CdTe to CdSe occurs on the 500 fs time scale in these heteromaterials.