TY - JOUR
T1 - Small-Band-Offset Perovskite Shells Increase Auger Lifetime in Quantum Dot Solids
AU - Quintero-Bermudez, Rafael
AU - Sabatini, Randy P.
AU - Lejay, Marc
AU - Voznyy, Oleksandr
AU - Sargent, Edward H.
N1 - Funding Information:
This publication is based in part on work supported by the Ontario Research Fund−Research Excellent Program and by the Natural Sciences and Engineering Research Council (NSERC) of Canada, in particular NSERC Strategic Partnership grant no. 478954-15. We thank Sjoerd Hoogland, Larissa Levina, Elenita Palmiano, Mengxia Liu, and James Fan for their assistance and insightful discussions.
Publisher Copyright:
© 2017 American Chemical Society.
PY - 2017/12/26
Y1 - 2017/12/26
N2 - Colloidal quantum dots (CQDs) enable low-cost, high-performance optoelectronic devices including photovoltaics, photodetectors, LEDs, and lasers. Continuous-wave lasing in the near-infrared remains to be realized based on such materials, yet a solution-processed NIR laser would be of use in communications and interconnects. In infrared quantum dots, long-lived gain is hampered by a high rate of Auger recombination. Here, we report the use of perovskite shells, grown on cores of IR-emitting PbS CQDs, and we thus reduce the rate of Auger recombination by up to 1 order of magnitude. We employ ultrafast transient absorption spectroscopy to isolate distinct Auger recombination phenomena and study the effect of bandstructure and passivation on Auger recombination. We corroborate the experimental findings with model-based investigations of Auger recombination in various CQD core-shell structures. We explain how the band alignment provided by perovskite shells comes close to the optimal required to suppress the Auger rate. These results provide a step along the path toward solution-processed near-infrared lasers.
AB - Colloidal quantum dots (CQDs) enable low-cost, high-performance optoelectronic devices including photovoltaics, photodetectors, LEDs, and lasers. Continuous-wave lasing in the near-infrared remains to be realized based on such materials, yet a solution-processed NIR laser would be of use in communications and interconnects. In infrared quantum dots, long-lived gain is hampered by a high rate of Auger recombination. Here, we report the use of perovskite shells, grown on cores of IR-emitting PbS CQDs, and we thus reduce the rate of Auger recombination by up to 1 order of magnitude. We employ ultrafast transient absorption spectroscopy to isolate distinct Auger recombination phenomena and study the effect of bandstructure and passivation on Auger recombination. We corroborate the experimental findings with model-based investigations of Auger recombination in various CQD core-shell structures. We explain how the band alignment provided by perovskite shells comes close to the optimal required to suppress the Auger rate. These results provide a step along the path toward solution-processed near-infrared lasers.
KW - Auger recombination
KW - infrared light emission
KW - perovskites
KW - quantum dots
KW - transient absorption spectroscopy
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U2 - 10.1021/acsnano.7b06363
DO - 10.1021/acsnano.7b06363
M3 - Article
C2 - 29227680
AN - SCOPUS:85039064180
SN - 1936-0851
VL - 11
SP - 12378
EP - 12384
JO - ACS nano
JF - ACS nano
IS - 12
ER -