TY - GEN
T1 - Photogeneration and recombination of multiexcitons in nanocrystal quantum dots in relation to solar energy conversion
AU - Klimov, Victor I.
PY - 2007/12/28
Y1 - 2007/12/28
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.
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M3 - Conference contribution
AN - SCOPUS:37349063405
SN - 084127438X
SN - 9780841274389
T3 - ACS National Meeting Book of Abstracts
BT - 233rd ACS National Meeting, Abstracts of Scientific Papers
T2 - 233rd ACS National Meeting
Y2 - 25 March 2007 through 29 March 2007
ER -