Electronic structure and photoexcited-carrier dynamics in nanometer-size CdSe clusters

M. G. Bawendi; W. L. Wilson; L. Rothberg; P. J. Carroll; T. M. Jedju; M. L. Steigerwald; L. E. Brus

doi:10.1103/PhysRevLett.65.1623

Electronic structure and photoexcited-carrier dynamics in nanometer-size CdSe clusters

M. G. Bawendi, W. L. Wilson, L. Rothberg, P. J. Carroll, T. M. Jedju, M. L. Steigerwald, and L. E. Brus

Phys. Rev. Lett. 65, 1623 – Published 24 September 1990

Abstract

We use transient optical hole burning and photoluminescence to investigate the static and dynamic electronic properties of 32-Å CdSe quantum dots. We observe a number of discrete electronic transitions, resolve LO-phonon progressions, and obtain homogeneous linewidths and electron–LO-phonon couplings. We find that the band-gap luminescence is not from the exciton state, but from a surface trapped state. Rapid (∼160 fs) trapping into these surface states results in long-lived (∼10–100 ns) bleach and induced-absorption features in pump-probe experiments.