Controlled Steric Hindrance Enables Efficient Ligand Exchange for Stable, Infrared-Bandgap Quantum Dot Inks

Mengxia Liu; Fanglin Che; Bin Sun; Oleksandr Voznyy; Andrew Proppe; Rahim Munir; Mingyang Wei; Rafael Quintero-Bermudez; Lilei Hu; Sjoerd Hoogland; Andreas Mandelis; Aram Amassian; Shana O. Kelley; F. Pelayo Garciá De Arquer; Edward H. Sargent

doi:10.1021/acsenergylett.9b00388

Controlled Steric Hindrance Enables Efficient Ligand Exchange for Stable, Infrared-Bandgap Quantum Dot Inks

Mengxia Liu, Fanglin Che, Bin Sun, Oleksandr Voznyy, Andrew Proppe, Rahim Munir, Mingyang Wei, Rafael Quintero-Bermudez, Lilei Hu, Sjoerd Hoogland, Andreas Mandelis, Aram Amassian, Shana O. Kelley, F. Pelayo Garciá De Arquer, Edward H. Sargent^*

^*Corresponding author for this work

Chemistry

Research output: Contribution to journal › Article › peer-review

65 Scopus citations

Abstract

Colloidal quantum dots (CQDs), which benefit from a size-tuned bandgap, are a solution-processed material for infrared energy harvesting. This characteristic enables the fabrication of solar cells that form tandem devices with silicon. Unfortunately, in the case of CQDs having diameters sufficiently large (>4 nm) so that the nanoparticles absorb light well beyond silicon's bandgap, conventional ligand exchanges fail. Here we report a strategy wherein short-chain carboxylates, used as a steric hindrance controller, facilitate the ligand exchange process on small-bandgap CQDs. We demonstrate that the net energy barrier to replace original capping ligands with lead halide anions is decreased when short carboxylates are involved. The approach produces more complete ligand exchange that enables improved packing density and monodispersity. This contributes to a 2-fold reduction in the trap state density compared to the best previously reported exchange. We demonstrate solar cells that achieve a record infrared photon-to-electron conversion efficiency at the excitonic peak.

Original language	English (US)
Pages (from-to)	1225-1230
Number of pages	6
Journal	ACS Energy Letters
Volume	4
Issue number	6
DOIs	https://doi.org/10.1021/acsenergylett.9b00388
State	Published - Jun 14 2019

Funding

This publication is based in part on work supported by the Ontario Research Fund Research Excellence Program and by the Natural Sciences and Engineering Research Council (NSERC) of Canada. Computations were performed on the Niagara supercomputer at the SciNet HPC Consortium. SciNet is funded by: the Canada Foundation for Innovation; the Government of Ontario; Ontario Research Fund Research Excellence Program; and the University of Toronto. The authors thank E. Palmiano, L. Levina, R. Wolowiec, and D. Kopilovic for their help during the course of this study.

ASJC Scopus subject areas

Chemistry (miscellaneous)
Renewable Energy, Sustainability and the Environment
Fuel Technology
Energy Engineering and Power Technology
Materials Chemistry

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

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10.1021/acsenergylett.9b00388

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Liu, M., Che, F., Sun, B., Voznyy, O., Proppe, A., Munir, R., Wei, M., Quintero-Bermudez, R., Hu, L., Hoogland, S., Mandelis, A., Amassian, A., Kelley, S. O., Garciá De Arquer, F. P., & Sargent, E. H. (2019). Controlled Steric Hindrance Enables Efficient Ligand Exchange for Stable, Infrared-Bandgap Quantum Dot Inks. ACS Energy Letters, 4(6), 1225-1230. https://doi.org/10.1021/acsenergylett.9b00388

@article{d107e322e1c740e7a98bbfc1f27b590c,

title = "Controlled Steric Hindrance Enables Efficient Ligand Exchange for Stable, Infrared-Bandgap Quantum Dot Inks",

abstract = "Colloidal quantum dots (CQDs), which benefit from a size-tuned bandgap, are a solution-processed material for infrared energy harvesting. This characteristic enables the fabrication of solar cells that form tandem devices with silicon. Unfortunately, in the case of CQDs having diameters sufficiently large (>4 nm) so that the nanoparticles absorb light well beyond silicon's bandgap, conventional ligand exchanges fail. Here we report a strategy wherein short-chain carboxylates, used as a steric hindrance controller, facilitate the ligand exchange process on small-bandgap CQDs. We demonstrate that the net energy barrier to replace original capping ligands with lead halide anions is decreased when short carboxylates are involved. The approach produces more complete ligand exchange that enables improved packing density and monodispersity. This contributes to a 2-fold reduction in the trap state density compared to the best previously reported exchange. We demonstrate solar cells that achieve a record infrared photon-to-electron conversion efficiency at the excitonic peak.",

author = "Mengxia Liu and Fanglin Che and Bin Sun and Oleksandr Voznyy and Andrew Proppe and Rahim Munir and Mingyang Wei and Rafael Quintero-Bermudez and Lilei Hu and Sjoerd Hoogland and Andreas Mandelis and Aram Amassian and Kelley, {Shana O.} and {Garci{\'a} De Arquer}, {F. Pelayo} and Sargent, {Edward H.}",

note = "Funding Information: This publication is based in part on work supported by the Ontario Research Fund Research Excellence Program and by the Natural Sciences and Engineering Research Council (NSERC) of Canada. Computations were performed on the Niagara supercomputer at the SciNet HPC Consortium. SciNet is funded by: the Canada Foundation for Innovation; the Government of Ontario; Ontario Research Fund Research Excellence Program; and the University of Toronto. The authors thank E. Palmiano, L. Levina, R. Wolowiec, and D. Kopilovic for their help during the course of this study. Publisher Copyright: {\textcopyright} 2019 American Chemical Society.",

year = "2019",

month = jun,

day = "14",

doi = "10.1021/acsenergylett.9b00388",

language = "English (US)",

volume = "4",

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Liu, M, Che, F, Sun, B, Voznyy, O, Proppe, A, Munir, R, Wei, M, Quintero-Bermudez, R, Hu, L, Hoogland, S, Mandelis, A, Amassian, A, Kelley, SO, Garciá De Arquer, FP & Sargent, EH 2019, 'Controlled Steric Hindrance Enables Efficient Ligand Exchange for Stable, Infrared-Bandgap Quantum Dot Inks', ACS Energy Letters, vol. 4, no. 6, pp. 1225-1230. https://doi.org/10.1021/acsenergylett.9b00388

TY - JOUR

T1 - Controlled Steric Hindrance Enables Efficient Ligand Exchange for Stable, Infrared-Bandgap Quantum Dot Inks

AU - Liu, Mengxia

AU - Che, Fanglin

AU - Sun, Bin

AU - Voznyy, Oleksandr

AU - Proppe, Andrew

AU - Munir, Rahim

AU - Wei, Mingyang

AU - Quintero-Bermudez, Rafael

AU - Hu, Lilei

AU - Hoogland, Sjoerd

AU - Mandelis, Andreas

AU - Amassian, Aram

AU - Kelley, Shana O.

AU - Garciá De Arquer, F. Pelayo

AU - Sargent, Edward H.

N1 - Funding Information: This publication is based in part on work supported by the Ontario Research Fund Research Excellence Program and by the Natural Sciences and Engineering Research Council (NSERC) of Canada. Computations were performed on the Niagara supercomputer at the SciNet HPC Consortium. SciNet is funded by: the Canada Foundation for Innovation; the Government of Ontario; Ontario Research Fund Research Excellence Program; and the University of Toronto. The authors thank E. Palmiano, L. Levina, R. Wolowiec, and D. Kopilovic for their help during the course of this study. Publisher Copyright: © 2019 American Chemical Society.

PY - 2019/6/14

Y1 - 2019/6/14

N2 - Colloidal quantum dots (CQDs), which benefit from a size-tuned bandgap, are a solution-processed material for infrared energy harvesting. This characteristic enables the fabrication of solar cells that form tandem devices with silicon. Unfortunately, in the case of CQDs having diameters sufficiently large (>4 nm) so that the nanoparticles absorb light well beyond silicon's bandgap, conventional ligand exchanges fail. Here we report a strategy wherein short-chain carboxylates, used as a steric hindrance controller, facilitate the ligand exchange process on small-bandgap CQDs. We demonstrate that the net energy barrier to replace original capping ligands with lead halide anions is decreased when short carboxylates are involved. The approach produces more complete ligand exchange that enables improved packing density and monodispersity. This contributes to a 2-fold reduction in the trap state density compared to the best previously reported exchange. We demonstrate solar cells that achieve a record infrared photon-to-electron conversion efficiency at the excitonic peak.

AB - Colloidal quantum dots (CQDs), which benefit from a size-tuned bandgap, are a solution-processed material for infrared energy harvesting. This characteristic enables the fabrication of solar cells that form tandem devices with silicon. Unfortunately, in the case of CQDs having diameters sufficiently large (>4 nm) so that the nanoparticles absorb light well beyond silicon's bandgap, conventional ligand exchanges fail. Here we report a strategy wherein short-chain carboxylates, used as a steric hindrance controller, facilitate the ligand exchange process on small-bandgap CQDs. We demonstrate that the net energy barrier to replace original capping ligands with lead halide anions is decreased when short carboxylates are involved. The approach produces more complete ligand exchange that enables improved packing density and monodispersity. This contributes to a 2-fold reduction in the trap state density compared to the best previously reported exchange. We demonstrate solar cells that achieve a record infrared photon-to-electron conversion efficiency at the excitonic peak.

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DO - 10.1021/acsenergylett.9b00388

M3 - Article

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EP - 1230

JO - ACS Energy Letters

JF - ACS Energy Letters

IS - 6

ER -

Controlled Steric Hindrance Enables Efficient Ligand Exchange for Stable, Infrared-Bandgap Quantum Dot Inks

Abstract

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ASJC Scopus subject areas

UN SDGs

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