Direct femtosecond observation of charge carrier recombination in ternary semiconductor nanocrystals: The effect of composition and shelling

Handle URI:
http://hdl.handle.net/10754/564057
Title:
Direct femtosecond observation of charge carrier recombination in ternary semiconductor nanocrystals: The effect of composition and shelling
Authors:
Bose, Riya; Ahmed, Ghada H. ( 0000-0003-1709-8692 ) ; Alarousu, Erkki; Parida, Manas R.; Abdelhady, Ahmed L.; Bakr, Osman M. ( 0000-0002-3428-1002 ) ; Mohammed, Omar F. ( 0000-0001-8500-1130 )
Abstract:
Heavy-metal free ternary semiconductor nanocrystals are emerging as key materials in photoactive applications. However, the relative abundance of intra-bandgap defect states and lack of understanding of their origins within this class of nanocrystals are major factors limiting their applicability. To remove these undesirable defect states which considerably shorten the lifetimes of photogenerated excited carriers, a detailed understanding about their origin and nature is required. In this report, we monitor the ultrafast charge carrier dynamics of CuInS2 (CIS), CuInSSe (CISSe), and CuInSe2 (CISe) nanocrystals, before and after ZnS shelling, using state-of-the-art time-resolved laser spectroscopy with broadband capabilities. The experimental results demonstrate the presence of both electron and hole trapping intra-bandgap states in the nanocrystals which can be removed significantly by ZnS shelling, and the carrier dynamics is slowed down. Another important observation remains the reduction of carrier lifetime in the presence of Se, and the shelling strategy is observed to be less effective at suppressing trap states. This study provides quantitative physical insights into the role of anion composition and shelling on the charge carrier dynamics in ternary CIS, CISSe, and CISe nanocrystals which are essential to improve their applicability for photovoltaics and optoelectronics.
KAUST Department:
KAUST Solar Center (KSC); Physical Sciences and Engineering (PSE) Division; KAUST Catalysis Center (KCC); Chemical Science Program; Materials Science and Engineering Program; Functional Nanomaterials Lab (FuNL)
Publisher:
American Chemical Society (ACS)
Journal:
The Journal of Physical Chemistry C
Issue Date:
12-Feb-2015
DOI:
10.1021/acs.jpcc.5b00204
Type:
Article
ISSN:
19327447
Sponsors:
R.B. is grateful for the postdoctoral fellowship provided by Saudi Basic Industries Corporation (SABIC). The work reported here was supported by the King Abdullah University of Science and Technology.
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Chemical Science Program; Materials Science and Engineering Program; KAUST Catalysis Center (KCC); KAUST Solar Center (KSC)

Full metadata record

DC FieldValue Language
dc.contributor.authorBose, Riyaen
dc.contributor.authorAhmed, Ghada H.en
dc.contributor.authorAlarousu, Erkkien
dc.contributor.authorParida, Manas R.en
dc.contributor.authorAbdelhady, Ahmed L.en
dc.contributor.authorBakr, Osman M.en
dc.contributor.authorMohammed, Omar F.en
dc.date.accessioned2015-08-03T12:30:10Zen
dc.date.available2015-08-03T12:30:10Zen
dc.date.issued2015-02-12en
dc.identifier.issn19327447en
dc.identifier.doi10.1021/acs.jpcc.5b00204en
dc.identifier.urihttp://hdl.handle.net/10754/564057en
dc.description.abstractHeavy-metal free ternary semiconductor nanocrystals are emerging as key materials in photoactive applications. However, the relative abundance of intra-bandgap defect states and lack of understanding of their origins within this class of nanocrystals are major factors limiting their applicability. To remove these undesirable defect states which considerably shorten the lifetimes of photogenerated excited carriers, a detailed understanding about their origin and nature is required. In this report, we monitor the ultrafast charge carrier dynamics of CuInS2 (CIS), CuInSSe (CISSe), and CuInSe2 (CISe) nanocrystals, before and after ZnS shelling, using state-of-the-art time-resolved laser spectroscopy with broadband capabilities. The experimental results demonstrate the presence of both electron and hole trapping intra-bandgap states in the nanocrystals which can be removed significantly by ZnS shelling, and the carrier dynamics is slowed down. Another important observation remains the reduction of carrier lifetime in the presence of Se, and the shelling strategy is observed to be less effective at suppressing trap states. This study provides quantitative physical insights into the role of anion composition and shelling on the charge carrier dynamics in ternary CIS, CISSe, and CISe nanocrystals which are essential to improve their applicability for photovoltaics and optoelectronics.en
dc.description.sponsorshipR.B. is grateful for the postdoctoral fellowship provided by Saudi Basic Industries Corporation (SABIC). The work reported here was supported by the King Abdullah University of Science and Technology.en
dc.publisherAmerican Chemical Society (ACS)en
dc.titleDirect femtosecond observation of charge carrier recombination in ternary semiconductor nanocrystals: The effect of composition and shellingen
dc.typeArticleen
dc.contributor.departmentKAUST Solar Center (KSC)en
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentKAUST Catalysis Center (KCC)en
dc.contributor.departmentChemical Science Programen
dc.contributor.departmentMaterials Science and Engineering Programen
dc.contributor.departmentFunctional Nanomaterials Lab (FuNL)en
dc.identifier.journalThe Journal of Physical Chemistry Cen
kaust.authorBose, Riyaen
kaust.authorAlarousu, Erkkien
kaust.authorParida, Manas R.en
kaust.authorAbdelhady, Ahmed L.en
kaust.authorBakr, Osman M.en
kaust.authorMohammed, Omar F.en
kaust.authorAhmed, Ghada H.en
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