Abstract
Nonblinking excitonic emission from near-infrared and type-II nanocrystal quantum dots (NQDs) is reported for the first time. To realize this unusual degree of stability at the single-dot level, novel InP/CdS core/shell NQDs were synthesized for a range of shell thicknesses (∼1-11 monolayers of CdS). Ensemble spectroscopy measurements (photoluminescence peak position and radiative lifetimes) and electronic structure calculations established the transition from type-I to type-II band alignment in these heterostructured NQDs. More significantly, single-NQD studies revealed clear evidence for blinking suppression that was not strongly shell-thickness dependent, while photobleaching and biexciton lifetimes trended explicitly with extent of shelling. Specifically, very long biexciton lifetimes-up to >7 ns-were obtained for the thickest-shell structures, indicating dramatic suppression of nonradiative Auger recombination. This new system demonstrates that electronic structure and shell thickness can be employed together to effect control over key single-dot and ensemble NQD photophysical properties.
| Original language | English |
|---|---|
| Pages (from-to) | 5545-5551 |
| Number of pages | 7 |
| Journal | Nano Letters |
| Volume | 12 |
| Issue number | 11 |
| DOIs | |
| Publication status | Published - Nov 14 2012 |
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Keywords
- Auger recombination
- biexciton lifetime
- core/shell heterostructure
- Fluorescence blinking suppression
- near-infrared
- type-II nanocrystal quantum dot
ASJC Scopus subject areas
- Condensed Matter Physics
- Bioengineering
- Chemistry(all)
- Materials Science(all)
- Mechanical Engineering
Cite this
Suppressed blinking and auger recombination in near-infrared type-II InP/CdS nanocrystal quantum dots. / Dennis, Allison M.; Mangum, Benjamin D.; Piryatinski, Andrei; Park, Young Shin; Hannah, Daniel C.; Casson, Joanna L.; Williams, Darrick J.; Schaller, Richard D; Htoon, Han; Hollingsworth, Jennifer A.
In: Nano Letters, Vol. 12, No. 11, 14.11.2012, p. 5545-5551.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Suppressed blinking and auger recombination in near-infrared type-II InP/CdS nanocrystal quantum dots
AU - Dennis, Allison M.
AU - Mangum, Benjamin D.
AU - Piryatinski, Andrei
AU - Park, Young Shin
AU - Hannah, Daniel C.
AU - Casson, Joanna L.
AU - Williams, Darrick J.
AU - Schaller, Richard D
AU - Htoon, Han
AU - Hollingsworth, Jennifer A.
PY - 2012/11/14
Y1 - 2012/11/14
N2 - Nonblinking excitonic emission from near-infrared and type-II nanocrystal quantum dots (NQDs) is reported for the first time. To realize this unusual degree of stability at the single-dot level, novel InP/CdS core/shell NQDs were synthesized for a range of shell thicknesses (∼1-11 monolayers of CdS). Ensemble spectroscopy measurements (photoluminescence peak position and radiative lifetimes) and electronic structure calculations established the transition from type-I to type-II band alignment in these heterostructured NQDs. More significantly, single-NQD studies revealed clear evidence for blinking suppression that was not strongly shell-thickness dependent, while photobleaching and biexciton lifetimes trended explicitly with extent of shelling. Specifically, very long biexciton lifetimes-up to >7 ns-were obtained for the thickest-shell structures, indicating dramatic suppression of nonradiative Auger recombination. This new system demonstrates that electronic structure and shell thickness can be employed together to effect control over key single-dot and ensemble NQD photophysical properties.
AB - Nonblinking excitonic emission from near-infrared and type-II nanocrystal quantum dots (NQDs) is reported for the first time. To realize this unusual degree of stability at the single-dot level, novel InP/CdS core/shell NQDs were synthesized for a range of shell thicknesses (∼1-11 monolayers of CdS). Ensemble spectroscopy measurements (photoluminescence peak position and radiative lifetimes) and electronic structure calculations established the transition from type-I to type-II band alignment in these heterostructured NQDs. More significantly, single-NQD studies revealed clear evidence for blinking suppression that was not strongly shell-thickness dependent, while photobleaching and biexciton lifetimes trended explicitly with extent of shelling. Specifically, very long biexciton lifetimes-up to >7 ns-were obtained for the thickest-shell structures, indicating dramatic suppression of nonradiative Auger recombination. This new system demonstrates that electronic structure and shell thickness can be employed together to effect control over key single-dot and ensemble NQD photophysical properties.
KW - Auger recombination
KW - biexciton lifetime
KW - core/shell heterostructure
KW - Fluorescence blinking suppression
KW - near-infrared
KW - type-II nanocrystal quantum dot
UR - http://www.scopus.com/inward/record.url?scp=84869194058&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84869194058&partnerID=8YFLogxK
U2 - 10.1021/nl302453x
DO - 10.1021/nl302453x
M3 - Article
VL - 12
SP - 5545
EP - 5551
JO - Nano Letters
JF - Nano Letters
SN - 1530-6984
IS - 11
ER -