Spectroscopy and control of near-surface defects in conductive thin film ZnO

Handle URI:
http://hdl.handle.net/10754/607208
Title:
Spectroscopy and control of near-surface defects in conductive thin film ZnO
Authors:
Kelly, Leah L; Racke, David A; Schulz, Philip; Li, Hong; Winget, Paul; Kim, Hyungchul; Ndione, Paul; Sigdel, Ajaya K; Bredas, Jean-Luc ( 0000-0001-7278-4471 ) ; Berry, Joseph J; Graham, Samuel; Monti, Oliver L A
Abstract:
The electronic structure of inorganic semiconductor interfaces functionalized with extended π-conjugated organic molecules can be strongly influenced by localized gap states or point defects, often present at low concentrations and hard to identify spectroscopically. At the same time, in transparent conductive oxides such as ZnO, the presence of these gap states conveys the desirable high conductivity necessary for function as electron-selective interlayer or electron collection electrode in organic optoelectronic devices. Here, we report on the direct spectroscopic detection of a donor state within the band gap of highly conductive zinc oxide by two-photon photoemission spectroscopy. We show that adsorption of the prototypical organic acceptor C60 quenches this state by ground-state charge transfer, with immediate consequences on the interfacial energy level alignment. Comparison with computational results suggests the identity of the gap state as a near-surface-confined oxygen vacancy.
KAUST Department:
Solar and Photovoltaic Engineering Research Center (SPERC)
Citation:
Spectroscopy and control of near-surface defects in conductive thin film ZnO 2016, 28 (9):094007 Journal of Physics: Condensed Matter
Publisher:
IOP Publishing
Journal:
Journal of Physics: Condensed Matter
Issue Date:
12-Feb-2016
DOI:
10.1088/0953-8984/28/9/094007
Type:
Article
ISSN:
0953-8984; 1361-648X
Sponsors:
This work was supported as part of the Center for Interface Science: Solar Electric Materials (CISSEM), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award Number DE-SC0001084.
Additional Links:
http://stacks.iop.org/0953-8984/28/i=9/a=094007?key=crossref.f23aa26cd74fc8e4fb3da44c0fd1fc35
Appears in Collections:
Articles; Solar and Photovoltaic Engineering Research Center (SPERC)

Full metadata record

DC FieldValue Language
dc.contributor.authorKelly, Leah Len
dc.contributor.authorRacke, David Aen
dc.contributor.authorSchulz, Philipen
dc.contributor.authorLi, Hongen
dc.contributor.authorWinget, Paulen
dc.contributor.authorKim, Hyungchulen
dc.contributor.authorNdione, Paulen
dc.contributor.authorSigdel, Ajaya Ken
dc.contributor.authorBredas, Jean-Lucen
dc.contributor.authorBerry, Joseph Jen
dc.contributor.authorGraham, Samuelen
dc.contributor.authorMonti, Oliver L Aen
dc.date.accessioned2016-04-27T12:03:07Zen
dc.date.available2016-04-27T12:03:07Zen
dc.date.issued2016-02-12en
dc.identifier.citationSpectroscopy and control of near-surface defects in conductive thin film ZnO 2016, 28 (9):094007 Journal of Physics: Condensed Matteren
dc.identifier.issn0953-8984en
dc.identifier.issn1361-648Xen
dc.identifier.doi10.1088/0953-8984/28/9/094007en
dc.identifier.urihttp://hdl.handle.net/10754/607208en
dc.description.abstractThe electronic structure of inorganic semiconductor interfaces functionalized with extended π-conjugated organic molecules can be strongly influenced by localized gap states or point defects, often present at low concentrations and hard to identify spectroscopically. At the same time, in transparent conductive oxides such as ZnO, the presence of these gap states conveys the desirable high conductivity necessary for function as electron-selective interlayer or electron collection electrode in organic optoelectronic devices. Here, we report on the direct spectroscopic detection of a donor state within the band gap of highly conductive zinc oxide by two-photon photoemission spectroscopy. We show that adsorption of the prototypical organic acceptor C60 quenches this state by ground-state charge transfer, with immediate consequences on the interfacial energy level alignment. Comparison with computational results suggests the identity of the gap state as a near-surface-confined oxygen vacancy.en
dc.description.sponsorshipThis work was supported as part of the Center for Interface Science: Solar Electric Materials (CISSEM), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award Number DE-SC0001084.en
dc.language.isoenen
dc.publisherIOP Publishingen
dc.relation.urlhttp://stacks.iop.org/0953-8984/28/i=9/a=094007?key=crossref.f23aa26cd74fc8e4fb3da44c0fd1fc35en
dc.rightsArchived with thanks to Journal of Physics: Condensed Matteren
dc.titleSpectroscopy and control of near-surface defects in conductive thin film ZnOen
dc.typeArticleen
dc.contributor.departmentSolar and Photovoltaic Engineering Research Center (SPERC)en
dc.identifier.journalJournal of Physics: Condensed Matteren
dc.eprint.versionPost-printen
dc.contributor.institutionUniversity of Arizona, Department of Chemistry & Biochemistry, 1306 E. University Blvd., Tucson, Arizona 85721, USAen
dc.contributor.institutionNational Renewable Energy Laboratory, National Center for Photovoltaics, Golden, Colorado, 80401, USAen
dc.contributor.institutionPrinceton University, Department of Electrical Engineering, Princeton, New Jersey 08544, USAen
dc.contributor.institutionGeorgia Institute of Technology, School of Chemistry and Biochemistry and Center for Organic Photonics and Electronics, Atlanta, Georgia 30332–0400, USAen
dc.contributor.institutionUniversity of Arizona, Department of Physics, 1118 E. Fourth Street, Tucson, Arizona 85721, USA.en
dc.contributor.affiliationKing Abdullah University of Science and Technology (KAUST)en
kaust.authorBredas, Jean-Lucen
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