Origins of Stokes Shift in PbS Nanocrystals

Nano Letters
Oleksandr VoznyyEdward H Sargent

Abstract

Stokes shift, an energy difference between the excitonic absorption and emission, is a property of colloidal quantum dots (CQDs) typically ascribed to splitting between dark and bright excitons. In some materials, e.g., PbS, CuInS2, and CdHgTe, a Stokes shift of up to 200 meV is observed, substantially larger than the estimates of dark-bright state splitting or vibronic relaxations. The shift origin remains highly debated because contradictory signatures of both surface and bulk character were reported for the Stokes-shifted electronic state. Here, we show that the energy transfer among CQDs in a polydispersed ensemble in solution suffices to explain the excess Stokes shift. This energy transfer is primarily due to CQD aggregation and can be substantially eliminated by extreme dilution, higher-viscosity solvent, or better-dispersed colloids. Our findings highlight that ensemble polydispersity remains the primary source of the Stokes shift in CQDs in solution, propagating into the Stokes shift in films and the open-circuit voltage deficit in CQD solar cells. Improved synthetic control can bring notable advancements in CQD photovoltaics, and the Stokes shift continues to provide a sensitive and significant metric to monitor ensem...Continue Reading

References

Jun 15, 1996·Physical Review. B, Condensed Matter·D J NorrisM G Bawendi
Nov 13, 1995·Physical Review Letters·M NirmalM Rosen
Feb 26, 1996·Physical Review Letters·C R KaganM G Bawendi
May 12, 2005·Journal of the American Chemical Society·Kyung-Sang ChoChristopher B Murray
Dec 14, 2006·Nano Letters·J M AnAlex Zunger
Mar 12, 2009·Journal of the American Chemical Society·Jane Y RempelKlavs F Jensen
Oct 16, 2010·Nanotechnology·J E LewisX J Jiang
Jul 31, 2012·Nature Nanotechnology·Alexander H IpEdward H Sargent
May 25, 2013·ACS Nano·David ZhitomirskyEdward H Sargent
May 21, 2014·ACS Nano·Mark C WeidmanWilliam A Tisdale
Feb 17, 2015·ACS Nano·Natalia KholmichevaMikhail Zamkov
Apr 3, 2016·Angewandte Chemie·Roberto GrisorioCarlo Giansante
Jun 14, 2016·Nature Materials·Federica BertolottiNorberto Masciocchi
Sep 15, 2016·Nano Letters·Justin R CaramMoungi G Bawendi
Jan 20, 2017·Nano Letters·Rachel H GilmoreWilliam A Tisdale
Jan 20, 2017·Journal of the American Chemical Society·Michael P CamposJonathan S Owen

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Citations

Oct 11, 2019·Advanced Materials·James Z FanEdward H Sargent
Aug 19, 2020·Nanomaterials·Sung Hun KimHong Seok Lee
Oct 21, 2020·Small·Taewan KimJongmin Choi
May 25, 2021·The Journal of Physical Chemistry Letters·Augustin CaillasAloyse Degiron
Jun 5, 2021·Advanced Materials·Junwei LiuZhihua Zhou
Jul 21, 2021·Nature Communications·Guozheng ShiWanli Ma
Nov 14, 2019·ACS Nano·Miguel Albaladejo-SiguanYana Vaynzof
Jun 19, 2018·Nano Letters·Jea Woong JoEdward H Sargent
Jun 28, 2019·The Journal of Physical Chemistry Letters·Peng FanAnlian Pan
Sep 4, 2018·ACS Photonics·Annalisa BroduDaniel Vanmaekelbergh
Sep 20, 2019·The Journal of Physical Chemistry Letters·Philippe B GreenMark W B Wilson
Sep 21, 2019·ACS Nano·Oleksandr VoznyyEdward H Sargent
Oct 22, 2020·ACS Applied Materials & Interfaces·Chandan MahajanArup K Rath
Sep 16, 2020·The Journal of Physical Chemistry Letters·Sebastian VolkVanessa Wood
Sep 4, 2021·ACS Energy Letters·Benjamin DaiberBruno Ehrler

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