Abstract
PbSe nanocrystal colloids exhibit a well-defined excitonic structure with the lowest energy exciton tuning from 0.5 to 1 eV, as a function of size. Band-edge fluorescence is observed from 1.2 to 2 μm with a small Stokes shift, sub-μs lifetime, and near-unity quantum yield. Upon pumping at 1.064 μm, the first exciton decay is consistent with radiative relaxation at low pump intensity and with Auger recombination at higher pump intensities. Optically induced absorption is observed at approximately midgap. These transitions exhibit strengths similar to the interband exciton and are size-tunable. They are assigned to the 1Se,h−1Pe,h and 1Pe,h−1De,h intraband excitations. Intraband pump−probe measurements of the 1Se,h−1Pe,h transition reveal a short lifetime and the absence of the phonon bottleneck.
Keywords
Affiliated Institutions
Related Publications
Organic-Capped ZnO Nanocrystals: Synthesis and n-Type Character
Wurtzite ZnO nanocrystals capped with trioctylphosphine oxide or alkylamines are synthesized and characterized. These ZnO nanocrystals can be made n-type either by electron tran...
Synthesis and Characterization of Strongly Luminescing ZnS-Capped CdSe Nanocrystals
We describe the synthesis of ZnS-capped CdSe semiconductor nanocrystals using organometallic reagents by a two-step single-flask method. X-ray photoelectron spectroscopy, transm...
Publication Info
- Year
- 2002
- Type
- article
- Volume
- 106
- Issue
- 41
- Pages
- 10634-10640
- Citations
- 648
- Access
- Closed
External Links
Social Impact
Social media, news, blog, policy document mentions
Citation Metrics
Cite This
Identifiers
- DOI
- 10.1021/jp021187e