Efficient Steplike Carrier Multiplication in Percolative Networks of Epitaxially Connected PbSe Nanocrystals

Kulkarni, Aditya; Evers, Wiel H.; Tomic, Stanko; Beard, Matthew C.; Vanmaekelbergh, Daniel; Siebbeles, Laurens D. A.

doi:10.1021/acsnano.7b06511

Title: Efficient Steplike Carrier Multiplication in Percolative Networks of Epitaxially Connected PbSe Nanocrystals

Abstract

Here, carrier multiplication (CM) is a process in which a single photon excites two or more electrons. CM is of interest to enhance the efficiency of a solar cell. Until now, CM in thin films and solar cells of semiconductor nanocrystals (NCs) has been found at photon energies well above the minimum required energy of twice the band gap. The high threshold of CM strongly limits the benefits for solar cell applications. We show that CM is more efficient in a percolative network of directly connected PbSe NCs. The CM threshold is at twice the band gap and increases in a steplike fashion with photon energy. A lower CM efficiency is found for a solid of weaker coupled NCs. This demonstrates that the coupling between NCs strongly affects the CM efficiency. According to device simulations, the measured CM efficiency would significantly enhance the power conversion efficiency of a solar cell.

Authors:

^[1]; Evers, Wiel H. ^[1];

^[2];

^[3];

^[4];

^[1]

Delft Univ. of Technology, Delft (The Netherlands)
Univ. of Salford, Manchester (United Kingdom)
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Univ. of Utrecht, Utrecht (The Netherlands)

Publication Date:: Thu Dec 14 00:00:00 EST 2017

Research Org.:: National Renewable Energy Laboratory (NREL), Golden, CO (United States)

Sponsoring Org.:: USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:: 1416716

Report Number(s):: NREL/JA-5900-68940
Journal ID: ISSN 1936-0851

Grant/Contract Number:: AC36-08GO28308

Resource Type:: Accepted Manuscript

Journal Name:: ACS Nano

Additional Journal Information:: Journal Volume: 12; Journal Issue: 1; Journal ID: ISSN 1936-0851

Publisher:: American Chemical Society (ACS)

Country of Publication:: United States

Language:: English

Subject:: 14 SOLAR ENERGY; 77 NANOSCIENCE AND NANOTECHNOLOGY; carrier multiplication; charge carrier mobility; nanocrystal networks; solar cell efficiency; terahertz spectroscopy

Citation Formats


                    Kulkarni, Aditya, Evers, Wiel H., Tomic, Stanko, Beard, Matthew C., Vanmaekelbergh, Daniel, and Siebbeles, Laurens D. A. Efficient Steplike Carrier Multiplication in Percolative Networks of Epitaxially Connected PbSe Nanocrystals.  United States: N. p., 2017. 
Web.  doi:10.1021/acsnano.7b06511.

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                    Kulkarni, Aditya, Evers, Wiel H., Tomic, Stanko, Beard, Matthew C., Vanmaekelbergh, Daniel, & Siebbeles, Laurens D. A. Efficient Steplike Carrier Multiplication in Percolative Networks of Epitaxially Connected PbSe Nanocrystals.  United States.  https://doi.org/10.1021/acsnano.7b06511

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                    Kulkarni, Aditya, Evers, Wiel H., Tomic, Stanko, Beard, Matthew C., Vanmaekelbergh, Daniel, and Siebbeles, Laurens D. A. Thu .  
"Efficient Steplike Carrier Multiplication in Percolative Networks of Epitaxially Connected PbSe Nanocrystals".  United States.  https://doi.org/10.1021/acsnano.7b06511.  https://www.osti.gov/servlets/purl/1416716.

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@article{osti_1416716,

  title        = {Efficient Steplike Carrier Multiplication in Percolative Networks of Epitaxially Connected PbSe Nanocrystals},

  author       = {Kulkarni, Aditya and Evers, Wiel H. and Tomic, Stanko and Beard, Matthew C. and Vanmaekelbergh, Daniel and Siebbeles, Laurens D. A.},

  abstractNote = {Here, carrier multiplication (CM) is a process in which a single photon excites two or more electrons. CM is of interest to enhance the efficiency of a solar cell. Until now, CM in thin films and solar cells of semiconductor nanocrystals (NCs) has been found at photon energies well above the minimum required energy of twice the band gap. The high threshold of CM strongly limits the benefits for solar cell applications. We show that CM is more efficient in a percolative network of directly connected PbSe NCs. The CM threshold is at twice the band gap and increases in a steplike fashion with photon energy. A lower CM efficiency is found for a solid of weaker coupled NCs. This demonstrates that the coupling between NCs strongly affects the CM efficiency. According to device simulations, the measured CM efficiency would significantly enhance the power conversion efficiency of a solar cell.},

  doi          = {10.1021/acsnano.7b06511},

  journal      = {ACS Nano},

  number       = 1,

  volume       = 12,

  place        = {United States},

  year         = {Thu Dec 14 00:00:00 EST 2017},

  month        = {Thu Dec 14 00:00:00 EST 2017}

}

Copy to clipboard

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Works referenced in this record:

Third Generation Photovoltaics based on Multiple Exciton Generation in Quantum Confined Semiconductors
journal, October 2012

Beard, Matthew C.; Luther, Joseph M.; Semonin, Octavi E.
Accounts of Chemical Research, Vol. 46, Issue 6
DOI: 10.1021/ar3001958

Multiple-exciton generation in lead selenide nanorod solar cells with external quantum efficiencies exceeding 120%
journal, September 2015

Davis, Nathaniel J. L. K.; Böhm, Marcus L.; Tabachnyk, Maxim
Nature Communications, Vol. 6, Issue 1
DOI: 10.1038/ncomms9259

Effect of Solar Concentration on the Thermodynamic Power Conversion Efficiency of Quantum-Dot Solar Cells Exhibiting Multiple Exciton Generation
journal, September 2012

Hanna, Mark C.; Beard, Matthew C.; Nozik, Arthur J.
The Journal of Physical Chemistry Letters, Vol. 3, Issue 19
DOI: 10.1021/jz301077e

Quantum dot solar cells
journal, April 2002

Nozik, A. J.
Physica E: Low-dimensional Systems and Nanostructures, Vol. 14, Issue 1-2, p. 115-120
DOI: 10.1016/S1386-9477(02)00374-0

Peak External Photocurrent Quantum Efficiency Exceeding 100% via MEG in a Quantum Dot Solar Cell
journal, December 2011

Semonin, O. E.; Luther, J. M.; Choi, S.
Science, Vol. 334, Issue 6062
DOI: 10.1126/science.1209845

Generating Free Charges by Carrier Multiplication in Quantum Dots for Highly Efficient Photovoltaics
journal, January 2015

ten Cate, Sybren; Sandeep, C. S. Suchand; Liu, Yao
Accounts of Chemical Research, Vol. 48, Issue 2
DOI: 10.1021/ar500248g

In Spite of Recent Doubts Carrier Multiplication Does Occur in PbSe Nanocrystals
journal, June 2008

Trinh, M. Tuan; Houtepen, Arjan J.; Schins, Juleon M.
Nano Letters, Vol. 8, Issue 6
DOI: 10.1021/nl0807225

Highly Efficient Multiple Exciton Generation in Colloidal PbSe and PbS Quantum Dots
journal, May 2005

Ellingson, Randy J.; Beard, Matthew C.; Johnson, Justin C.
Nano Letters, Vol. 5, Issue 5, p. 865-871
DOI: 10.1021/nl0502672

Multiple Exciton Generation in Colloidal Nanocrystals
journal, December 2013

Smith, Charles; Binks, David
Nanomaterials, Vol. 4, Issue 1
DOI: 10.3390/nano4010019

Free Charges Produced by Carrier Multiplication in Strongly Coupled PbSe Quantum Dot Films
journal, October 2011

Aerts, Michiel; Suchand Sandeep, C. S.; Gao, Yunan
Nano Letters, Vol. 11, Issue 10
DOI: 10.1021/nl202915p

High charge-carrier mobility enables exploitation of carrier multiplication in quantum-dot films
journal, August 2013

Sandeep, C. S. Suchand; Cate, Sybren ten; Schins, Juleon M.
Nature Communications, Vol. 4, Issue 1
DOI: 10.1038/ncomms3360

Enhanced Multiple Exciton Generation in Quasi-One-Dimensional Semiconductors
journal, August 2011

Cunningham, Paul D.; Boercker, Janice E.; Foos, Edward E.
Nano Letters, Vol. 11, Issue 8
DOI: 10.1021/nl202014a

Aspect Ratio Dependence of Auger Recombination and Carrier Multiplication in PbSe Nanorods
journal, February 2013

Padilha, Lazaro A.; Stewart, John T.; Sandberg, Richard L.
Nano Letters, Vol. 13, Issue 3
DOI: 10.1021/nl304426y

Carrier Multiplication in Semiconductor Nanocrystals: Influence of Size, Shape, and Composition
journal, March 2013

Padilha, Lazaro A.; Stewart, John T.; Sandberg, Richard L.
Accounts of Chemical Research, Vol. 46, Issue 6
DOI: 10.1021/ar300228x

Highly efficient carrier multiplication in PbS nanosheets
journal, April 2014

Aerts, Michiel; Bielewicz, Thomas; Klinke, Christian
Nature Communications, Vol. 5, Issue 1
DOI: 10.1038/ncomms4789

Assessment of carrier-multiplication efficiency in bulk PbSe and PbS
journal, September 2009

Pijpers, J. J. H.; Ulbricht, R.; Tielrooij, K. J.
Nature Physics, Vol. 5, Issue 11
DOI: 10.1038/nphys1393

Lifetime, Mobility, and Diffusion of Photoexcited Carriers in Ligand-Exchanged Lead Selenide Nanocrystal Films Measured by Time-Resolved Terahertz Spectroscopy
journal, January 2015

Guglietta, Glenn W.; Diroll, Benjamin T.; Gaulding, E. Ashley
ACS Nano, Vol. 9, Issue 2
DOI: 10.1021/nn506724h

Unity quantum yield of photogenerated charges and band-like transport in quantum-dot solids
journal, September 2011

Talgorn, Elise; Gao, Yunan; Aerts, Michiel
Nature Nanotechnology, Vol. 6, Issue 11
DOI: 10.1038/nnano.2011.159

Epitaxially Connected PbSe Quantum-Dot Films: Controlled Neck Formation and Optoelectronic Properties
journal, October 2014

Sandeep, C. S. Suchand; Azpiroz, Jon Mikel; Evers, Wiel H.
ACS Nano, Vol. 8, Issue 11
DOI: 10.1021/nn504679k

Low-Dimensional Semiconductor Superlattices Formed by Geometric Control over Nanocrystal Attachment
journal, November 2012

Evers, Wiel H.; Goris, Bart; Bals, Sara
Nano Letters, Vol. 13, Issue 6
DOI: 10.1021/nl303322k

In situ study of the formation mechanism of two-dimensional superlattices from PbSe nanocrystals
journal, September 2016

Geuchies, Jaco J.; van Overbeek, Carlo; Evers, Wiel H.
Nature Materials, Vol. 15, Issue 12
DOI: 10.1038/nmat4746

Long-range orientation and atomic attachment of nanocrystals in 2D honeycomb superlattices
journal, May 2014

Boneschanscher, M. P.; Evers, W. H.; Geuchies, J. J.
Science, Vol. 344, Issue 6190
DOI: 10.1126/science.1252642

High charge mobility in two-dimensional percolative networks of PbSe quantum dots connected by atomic bonds
journal, September 2015

Evers, Wiel H.; Schins, Juleon M.; Aerts, Michiel
Nature Communications, Vol. 6, Issue 1
DOI: 10.1038/ncomms9195

Hole Cooling Is Much Faster than Electron Cooling in PbSe Quantum Dots
journal, December 2015

Spoor, Frank C. M.; Kunneman, Lucas T.; Evers, Wiel H.
ACS Nano, Vol. 10, Issue 1
DOI: 10.1021/acsnano.5b05731

Broadband Cooling Spectra of Hot Electrons and Holes in PbSe Quantum Dots
journal, May 2017

Spoor, Frank C. M.; Tomić, Stanko; Houtepen, Arjan J.
ACS Nano, Vol. 11, Issue 6
DOI: 10.1021/acsnano.7b02506

Extremely Efficient Multiple Electron-Hole Pair Generation in Carbon Nanotube Photodiodes
journal, September 2009

Gabor, N. M.; Zhong, Z.; Bosnick, K.
Science, Vol. 325, Issue 5946
DOI: 10.1126/science.1176112

Step-like enhancement of luminescence quantum yield of silicon nanocrystals
journal, October 2011

Timmerman, D.; Valenta, J.; Dohnalová, K.
Nature Nanotechnology, Vol. 6, Issue 11
DOI: 10.1038/nnano.2011.167

Electronic structure and optical properties of PbS and PbSe quantum dots
journal, January 1997

Kang, Inuk; Wise, Frank W.
Journal of the Optical Society of America B, Vol. 14, Issue 7
DOI: 10.1364/JOSAB.14.001632

Fluorescence of colloidal PbSe/PbS QDs in NIR luminescent solar concentrators
journal, January 2012

Aeberhard, Urs; Vaxenburg, Roman; Lifshitz, Efrat
Physical Chemistry Chemical Physics, Vol. 14, Issue 47
DOI: 10.1039/c2cp42213a

The Peculiar Electronic Structure of PbSe Quantum Dots
journal, December 2006

An, J. M.; Franceschetti, A.; Dudiy, S. V.
Nano Letters, Vol. 6, Issue 12
DOI: 10.1021/nl061684x

Comparing Multiple Exciton Generation in Quantum Dots To Impact Ionization in Bulk Semiconductors: Implications for Enhancement of Solar Energy Conversion
journal, August 2010

Beard, Matthew C.; Midgett, Aaron G.; Hanna, Mark C.
Nano Letters, Vol. 10, Issue 8
DOI: 10.1021/nl101490z

Solar conversion efficiency of photovoltaic and photoelectrolysis cells with carrier multiplication absorbers
journal, October 2006

Hanna, M. C.; Nozik, A. J.
Journal of Applied Physics, Vol. 100, Issue 7
DOI: 10.1063/1.2356795

Radiative Efficiency Limit with Band Tailing Exceeds 30% for Quantum Dot Solar Cells
journal, October 2017

Jean, Joel; Mahony, Thomas S.; Bozyigit, Deniz
ACS Energy Letters, Vol. 2, Issue 11
DOI: 10.1021/acsenergylett.7b00923

On the Mechanism of Lead Chalcogenide Nanocrystal Formation
journal, October 2006

Steckel, Jonathan S.; Yen, Brian K. H.; Oertel, David C.
Journal of the American Chemical Society, Vol. 128, Issue 40
DOI: 10.1021/ja062626g

Carrier dynamics in semiconductors studied with time-resolved terahertz spectroscopy
journal, June 2011

Ulbricht, Ronald; Hendry, Euan; Shan, Jie
Reviews of Modern Physics, Vol. 83, Issue 2
DOI: 10.1103/RevModPhys.83.543

A Review of the Terahertz Conductivity of Bulk and Nano-Materials
journal, May 2012

Lloyd-Hughes, James; Jeon, Tae-In
Journal of Infrared, Millimeter, and Terahertz Waves, Vol. 33, Issue 9
DOI: 10.1007/s10762-012-9905-y

Time-Resolved Photoconductivity of PbSe Nanocrystal Arrays ^†
journal, December 2006

Murphy, James E.; Beard, Matthew C.; Nozik, Arthur J.
The Journal of Physical Chemistry B, Vol. 110, Issue 50
DOI: 10.1021/jp0646123

Interchain effects in the ultrafast photophysics of a semiconducting polymer: $THz$ time-domain spectroscopy of thin films and isolated chains in solution
journal, March 2005

Hendry, E.; Koeberg, M.; Schins, J. M.
Physical Review B, Vol. 71, Issue 12
DOI: 10.1103/PhysRevB.71.125201

Far-Infrared Absorption of PbSe Nanorods
journal, July 2011

Hyun, Byung-Ryool; Bartnik, A. C.; Koh, Weon-kyu
Nano Letters, Vol. 11, Issue 7
DOI: 10.1021/nl201115h

Apparent Versus True Carrier Multiplication Yields in Semiconductor Nanocrystals
journal, June 2010

McGuire, John A.; Sykora, Milan; Joo, Jin
Nano Letters, Vol. 10, Issue 6
DOI: 10.1021/nl100177c

The Peculiar Electronic Structure of PbSe Quantum Dots
journal, December 2006

An, J. M.; Franceschetti, A.; Dudiy, S. V.
Nano Letters, Vol. 6, Issue 12
DOI: 10.1021/nl061684x

Lifetime, Mobility, and Diffusion of Photoexcited Carriers in Ligand-Exchanged Lead Selenide Nanocrystal Films Measured by Time-Resolved Terahertz Spectroscopy
journal, January 2015

Guglietta, Glenn W.; Diroll, Benjamin T.; Gaulding, E. Ashley
ACS Nano, Vol. 9, Issue 2
DOI: 10.1021/nn506724h

Highly efficient carrier multiplication in PbS nanosheets
journal, April 2014

Aerts, Michiel; Bielewicz, Thomas; Klinke, Christian
Nature Communications, Vol. 5, Issue 1
DOI: 10.1038/ncomms4789

In situ study of the formation mechanism of two-dimensional superlattices from PbSe nanocrystals
journal, September 2016

Geuchies, Jaco J.; van Overbeek, Carlo; Evers, Wiel H.
Nature Materials, Vol. 15, Issue 12
DOI: 10.1038/nmat4746

Works referencing / citing this record:

Efficient carrier multiplication in CsPbI3 perovskite nanocrystals
journal, October 2018

de Weerd, Chris; Gomez, Leyre; Capretti, Antonio
Nature Communications, Vol. 9, Issue 1
DOI: 10.1038/s41467-018-06721-0

Hybrid Oleate–Iodide Ligand Shell for Air-Stable PbSe Nanocrystals and Superstructures
journal, July 2019

Peters, J. L.; van der Bok, J. C.; Hofmann, J. P.
Chemistry of Materials, Vol. 31, Issue 15
DOI: 10.1021/acs.chemmater.9b01891

Model To Determine a Distinct Rate Constant for Carrier Multiplication from Experiments
journal, December 2018

Spoor, Frank C. M.; Grimaldi, Gianluca; Kinge, Sachin
ACS Applied Energy Materials, Vol. 2, Issue 1
DOI: 10.1021/acsaem.8b01779

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Title: Efficient Steplike Carrier Multiplication in Percolative Networks of Epitaxially Connected PbSe Nanocrystals

Abstract

Citation Formats

Third Generation Photovoltaics based on Multiple Exciton Generation in Quantum Confined Semiconductors journal, October 2012

Multiple-exciton generation in lead selenide nanorod solar cells with external quantum efficiencies exceeding 120% journal, September 2015

Effect of Solar Concentration on the Thermodynamic Power Conversion Efficiency of Quantum-Dot Solar Cells Exhibiting Multiple Exciton Generation journal, September 2012

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Peak External Photocurrent Quantum Efficiency Exceeding 100% via MEG in a Quantum Dot Solar Cell journal, December 2011

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Highly Efficient Multiple Exciton Generation in Colloidal PbSe and PbS Quantum Dots journal, May 2005

Multiple Exciton Generation in Colloidal Nanocrystals journal, December 2013

Free Charges Produced by Carrier Multiplication in Strongly Coupled PbSe Quantum Dot Films journal, October 2011

High charge-carrier mobility enables exploitation of carrier multiplication in quantum-dot films journal, August 2013

Enhanced Multiple Exciton Generation in Quasi-One-Dimensional Semiconductors journal, August 2011

Aspect Ratio Dependence of Auger Recombination and Carrier Multiplication in PbSe Nanorods journal, February 2013

Carrier Multiplication in Semiconductor Nanocrystals: Influence of Size, Shape, and Composition journal, March 2013

Highly efficient carrier multiplication in PbS nanosheets journal, April 2014

Assessment of carrier-multiplication efficiency in bulk PbSe and PbS journal, September 2009

Lifetime, Mobility, and Diffusion of Photoexcited Carriers in Ligand-Exchanged Lead Selenide Nanocrystal Films Measured by Time-Resolved Terahertz Spectroscopy journal, January 2015

Unity quantum yield of photogenerated charges and band-like transport in quantum-dot solids journal, September 2011

Epitaxially Connected PbSe Quantum-Dot Films: Controlled Neck Formation and Optoelectronic Properties journal, October 2014

Low-Dimensional Semiconductor Superlattices Formed by Geometric Control over Nanocrystal Attachment journal, November 2012

In situ study of the formation mechanism of two-dimensional superlattices from PbSe nanocrystals journal, September 2016

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High charge mobility in two-dimensional percolative networks of PbSe quantum dots connected by atomic bonds journal, September 2015

Hole Cooling Is Much Faster than Electron Cooling in PbSe Quantum Dots journal, December 2015

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Extremely Efficient Multiple Electron-Hole Pair Generation in Carbon Nanotube Photodiodes journal, September 2009

Step-like enhancement of luminescence quantum yield of silicon nanocrystals journal, October 2011

Electronic structure and optical properties of PbS and PbSe quantum dots journal, January 1997

Fluorescence of colloidal PbSe/PbS QDs in NIR luminescent solar concentrators journal, January 2012

The Peculiar Electronic Structure of PbSe Quantum Dots journal, December 2006

Comparing Multiple Exciton Generation in Quantum Dots To Impact Ionization in Bulk Semiconductors: Implications for Enhancement of Solar Energy Conversion journal, August 2010

Solar conversion efficiency of photovoltaic and photoelectrolysis cells with carrier multiplication absorbers journal, October 2006

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A Review of the Terahertz Conductivity of Bulk and Nano-Materials journal, May 2012

Time-Resolved Photoconductivity of PbSe Nanocrystal Arrays † journal, December 2006

Interchain effects in the ultrafast photophysics of a semiconducting polymer: THz time-domain spectroscopy of thin films and isolated chains in solution journal, March 2005

Far-Infrared Absorption of PbSe Nanorods journal, July 2011

Apparent Versus True Carrier Multiplication Yields in Semiconductor Nanocrystals journal, June 2010

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Lifetime, Mobility, and Diffusion of Photoexcited Carriers in Ligand-Exchanged Lead Selenide Nanocrystal Films Measured by Time-Resolved Terahertz Spectroscopy journal, January 2015

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Model To Determine a Distinct Rate Constant for Carrier Multiplication from Experiments journal, December 2018

Third Generation Photovoltaics based on Multiple Exciton Generation in Quantum Confined Semiconductors
journal, October 2012

Multiple-exciton generation in lead selenide nanorod solar cells with external quantum efficiencies exceeding 120%
journal, September 2015

Effect of Solar Concentration on the Thermodynamic Power Conversion Efficiency of Quantum-Dot Solar Cells Exhibiting Multiple Exciton Generation
journal, September 2012

Quantum dot solar cells
journal, April 2002

Peak External Photocurrent Quantum Efficiency Exceeding 100% via MEG in a Quantum Dot Solar Cell
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Generating Free Charges by Carrier Multiplication in Quantum Dots for Highly Efficient Photovoltaics
journal, January 2015

In Spite of Recent Doubts Carrier Multiplication Does Occur in PbSe Nanocrystals
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Highly Efficient Multiple Exciton Generation in Colloidal PbSe and PbS Quantum Dots
journal, May 2005

Multiple Exciton Generation in Colloidal Nanocrystals
journal, December 2013

Free Charges Produced by Carrier Multiplication in Strongly Coupled PbSe Quantum Dot Films
journal, October 2011

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journal, August 2013

Enhanced Multiple Exciton Generation in Quasi-One-Dimensional Semiconductors
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journal, February 2013

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High charge mobility in two-dimensional percolative networks of PbSe quantum dots connected by atomic bonds
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journal, May 2017

Extremely Efficient Multiple Electron-Hole Pair Generation in Carbon Nanotube Photodiodes
journal, September 2009

Step-like enhancement of luminescence quantum yield of silicon nanocrystals
journal, October 2011

Electronic structure and optical properties of PbS and PbSe quantum dots
journal, January 1997

Fluorescence of colloidal PbSe/PbS QDs in NIR luminescent solar concentrators
journal, January 2012

The Peculiar Electronic Structure of PbSe Quantum Dots
journal, December 2006

Comparing Multiple Exciton Generation in Quantum Dots To Impact Ionization in Bulk Semiconductors: Implications for Enhancement of Solar Energy Conversion
journal, August 2010

Solar conversion efficiency of photovoltaic and photoelectrolysis cells with carrier multiplication absorbers
journal, October 2006

Radiative Efficiency Limit with Band Tailing Exceeds 30% for Quantum Dot Solar Cells
journal, October 2017

On the Mechanism of Lead Chalcogenide Nanocrystal Formation
journal, October 2006

Carrier dynamics in semiconductors studied with time-resolved terahertz spectroscopy
journal, June 2011

A Review of the Terahertz Conductivity of Bulk and Nano-Materials
journal, May 2012

Time-Resolved Photoconductivity of PbSe Nanocrystal Arrays ^†
journal, December 2006

Interchain effects in the ultrafast photophysics of a semiconducting polymer: $THz$ time-domain spectroscopy of thin films and isolated chains in solution
journal, March 2005

Far-Infrared Absorption of PbSe Nanorods
journal, July 2011

Apparent Versus True Carrier Multiplication Yields in Semiconductor Nanocrystals
journal, June 2010

The Peculiar Electronic Structure of PbSe Quantum Dots
journal, December 2006

Lifetime, Mobility, and Diffusion of Photoexcited Carriers in Ligand-Exchanged Lead Selenide Nanocrystal Films Measured by Time-Resolved Terahertz Spectroscopy
journal, January 2015

Highly efficient carrier multiplication in PbS nanosheets
journal, April 2014

In situ study of the formation mechanism of two-dimensional superlattices from PbSe nanocrystals
journal, September 2016

Efficient carrier multiplication in CsPbI3 perovskite nanocrystals
journal, October 2018

Hybrid Oleate–Iodide Ligand Shell for Air-Stable PbSe Nanocrystals and Superstructures
journal, July 2019

Model To Determine a Distinct Rate Constant for Carrier Multiplication from Experiments
journal, December 2018