ACS Nano 2012-09-25

Exciton relaxation in PbSe nanorods.

Jun Yang, Byung-Ryool Hyun, Anthony J Basile, Frank W Wise

Index: ACS Nano 6(9) , 8120-7, (2012)

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Abstract

Measurements of the picosecond-time-scale dynamics of photoexcited electrons in PbSe nanorods are reported. The intraband (1Π → 1Σ) relaxation occurs with a time constant of ~500 fs, which corresponds to a fast energy-relaxation rate of ~0.6 eV/ps. The biexciton lifetime in PbSe nanorods is significantly (3-4 times) longer than the lifetime of PbSe quantum dots with the same energy gap, roughly as expected considering the increased volume. The multiexciton lifetimes of PbSe nanorods scale as expected for a bimolecular recombination mechanism. Implications of the observed relaxations will be discussed.