Abstract
One source of efficiency losses in photovoltaic cells is their transparency toward solar photons with energies below the band gap of the absorbing layer. This loss can be reduced using a process of up-conversion whereby two or more sub-band-gap photons generate a single above-gap exciton. Traditional approaches to up-conversion, such as nonlinear two-photon absorption (2PA) or triplet fusion, suffer from low efficiency at solar light intensities, a narrow absorption bandwidth, nonoptimal absorption energies, and difficulties for implementing in practical devices. Here we show that these deficiencies can be alleviated using the effect of Auger up-conversion in thick-shell PbSe/CdSe quantum dots. This process relies on Auger recombination whereby two low-energy, core-based excitons are converted into a single higher-energy, shell-based exciton. Compared to their monocomponent counterparts, the tailored PbSe/CdSe heterostructures feature enhanced absorption cross-sections, a higher efficiency of the “productive” Auger pathway involving re-excitation of a hole, and longer lifetimes of both core- and shell-localized excitons. These features lead to effective up-conversion cross-sections that are more than 6 orders of magnitude higher than for standard nonlinear 2PA, which allows for efficient up-conversion of continuous wave infrared light at intensities as low as a few watts per square centimeter.
| Original language | English |
|---|---|
| Pages (from-to) | 10829-10841 |
| Number of pages | 13 |
| Journal | ACS Nano |
| Volume | 10 |
| Issue number | 12 |
| DOIs | |
| Publication status | Published - Dec 27 2016 |
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Keywords
- Auger recombination
- Auger up-conversion
- biexciton
- core/shell PbSe/CdSe quantum dot
- single exciton
- trion
- two-photon absorption
- up-conversion
ASJC Scopus subject areas
- Materials Science(all)
- Engineering(all)
- Physics and Astronomy(all)
Cite this
Auger Up-Conversion of Low-Intensity Infrared Light in Engineered Quantum Dots. / Makarov, Nikolay S.; Lin, Qianglu; Pietryga, Jeffrey M.; Robel, István; Klimov, Victor I.
In: ACS Nano, Vol. 10, No. 12, 27.12.2016, p. 10829-10841.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Auger Up-Conversion of Low-Intensity Infrared Light in Engineered Quantum Dots
AU - Makarov, Nikolay S.
AU - Lin, Qianglu
AU - Pietryga, Jeffrey M.
AU - Robel, István
AU - Klimov, Victor I
PY - 2016/12/27
Y1 - 2016/12/27
N2 - One source of efficiency losses in photovoltaic cells is their transparency toward solar photons with energies below the band gap of the absorbing layer. This loss can be reduced using a process of up-conversion whereby two or more sub-band-gap photons generate a single above-gap exciton. Traditional approaches to up-conversion, such as nonlinear two-photon absorption (2PA) or triplet fusion, suffer from low efficiency at solar light intensities, a narrow absorption bandwidth, nonoptimal absorption energies, and difficulties for implementing in practical devices. Here we show that these deficiencies can be alleviated using the effect of Auger up-conversion in thick-shell PbSe/CdSe quantum dots. This process relies on Auger recombination whereby two low-energy, core-based excitons are converted into a single higher-energy, shell-based exciton. Compared to their monocomponent counterparts, the tailored PbSe/CdSe heterostructures feature enhanced absorption cross-sections, a higher efficiency of the “productive” Auger pathway involving re-excitation of a hole, and longer lifetimes of both core- and shell-localized excitons. These features lead to effective up-conversion cross-sections that are more than 6 orders of magnitude higher than for standard nonlinear 2PA, which allows for efficient up-conversion of continuous wave infrared light at intensities as low as a few watts per square centimeter.
AB - One source of efficiency losses in photovoltaic cells is their transparency toward solar photons with energies below the band gap of the absorbing layer. This loss can be reduced using a process of up-conversion whereby two or more sub-band-gap photons generate a single above-gap exciton. Traditional approaches to up-conversion, such as nonlinear two-photon absorption (2PA) or triplet fusion, suffer from low efficiency at solar light intensities, a narrow absorption bandwidth, nonoptimal absorption energies, and difficulties for implementing in practical devices. Here we show that these deficiencies can be alleviated using the effect of Auger up-conversion in thick-shell PbSe/CdSe quantum dots. This process relies on Auger recombination whereby two low-energy, core-based excitons are converted into a single higher-energy, shell-based exciton. Compared to their monocomponent counterparts, the tailored PbSe/CdSe heterostructures feature enhanced absorption cross-sections, a higher efficiency of the “productive” Auger pathway involving re-excitation of a hole, and longer lifetimes of both core- and shell-localized excitons. These features lead to effective up-conversion cross-sections that are more than 6 orders of magnitude higher than for standard nonlinear 2PA, which allows for efficient up-conversion of continuous wave infrared light at intensities as low as a few watts per square centimeter.
KW - Auger recombination
KW - Auger up-conversion
KW - biexciton
KW - core/shell PbSe/CdSe quantum dot
KW - single exciton
KW - trion
KW - two-photon absorption
KW - up-conversion
UR - http://www.scopus.com/inward/record.url?scp=85008325034&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85008325034&partnerID=8YFLogxK
U2 - 10.1021/acsnano.6b04928
DO - 10.1021/acsnano.6b04928
M3 - Article
AN - SCOPUS:85008325034
VL - 10
SP - 10829
EP - 10841
JO - ACS Nano
JF - ACS Nano
SN - 1936-0851
IS - 12
ER -