Abstract
A usual assumption is that absorption of a single photon by a material produces a single electron-hole pair (exciton), while the photon energy in excess of the energy gap is dissipated as heat. In 2004, we reported for the first time that nanocrystals of PbSe could respond to absorption of a single photon by producing two or more excitons with the unity probability (Phys. Rev. Lett. 92, 186601, 2004). More recently, we observed generation of up to seven excitons per absorbed photon (Nano Lett. 6, 424, 2006), which corresponds to the ultimate limit allowed by energy conservation for the excitation energy used in these measurements. This presentation discusses such aspects of multi-exciton generation in nanocrystals as characteristic time scales of this process, statistics of photogenerated multiexciton populations, the limits on photon-to-exciton conversion efficiencies, and implications of multiexciton generation in photovoltaics and photocatalysis.
| Original language | English |
|---|---|
| Title of host publication | ACS National Meeting Book of Abstracts |
| Publication status | Published - 2007 |
| Event | 233rd ACS National Meeting - Chicago, IL, United States Duration: Mar 25 2007 → Mar 29 2007 |
Other
| Other | 233rd ACS National Meeting |
|---|---|
| Country | United States |
| City | Chicago, IL |
| Period | 3/25/07 → 3/29/07 |
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ASJC Scopus subject areas
- Chemistry(all)
Cite this
Photogeneration and recombination of multiexcitons in nanocrystal quantum dots in relation to solar energy conversion. / Klimov, Victor I.
ACS National Meeting Book of Abstracts. 2007.Research output: Chapter in Book/Report/Conference proceeding › Conference contribution
}
TY - GEN
T1 - Photogeneration and recombination of multiexcitons in nanocrystal quantum dots in relation to solar energy conversion
AU - Klimov, Victor I
PY - 2007
Y1 - 2007
N2 - A usual assumption is that absorption of a single photon by a material produces a single electron-hole pair (exciton), while the photon energy in excess of the energy gap is dissipated as heat. In 2004, we reported for the first time that nanocrystals of PbSe could respond to absorption of a single photon by producing two or more excitons with the unity probability (Phys. Rev. Lett. 92, 186601, 2004). More recently, we observed generation of up to seven excitons per absorbed photon (Nano Lett. 6, 424, 2006), which corresponds to the ultimate limit allowed by energy conservation for the excitation energy used in these measurements. This presentation discusses such aspects of multi-exciton generation in nanocrystals as characteristic time scales of this process, statistics of photogenerated multiexciton populations, the limits on photon-to-exciton conversion efficiencies, and implications of multiexciton generation in photovoltaics and photocatalysis.
AB - A usual assumption is that absorption of a single photon by a material produces a single electron-hole pair (exciton), while the photon energy in excess of the energy gap is dissipated as heat. In 2004, we reported for the first time that nanocrystals of PbSe could respond to absorption of a single photon by producing two or more excitons with the unity probability (Phys. Rev. Lett. 92, 186601, 2004). More recently, we observed generation of up to seven excitons per absorbed photon (Nano Lett. 6, 424, 2006), which corresponds to the ultimate limit allowed by energy conservation for the excitation energy used in these measurements. This presentation discusses such aspects of multi-exciton generation in nanocrystals as characteristic time scales of this process, statistics of photogenerated multiexciton populations, the limits on photon-to-exciton conversion efficiencies, and implications of multiexciton generation in photovoltaics and photocatalysis.
UR - http://www.scopus.com/inward/record.url?scp=37349063405&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=37349063405&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:37349063405
SN - 084127438X
SN - 9780841274389
BT - ACS National Meeting Book of Abstracts
ER -