Crossover from band-like to thermally activated charge transport in organic transistors due to strain-induced traps

Handle URI:
http://hdl.handle.net/10754/625330
Title:
Crossover from band-like to thermally activated charge transport in organic transistors due to strain-induced traps
Authors:
Mei, Yaochuan; Diemer, Peter J.; Niazi, Muhammad Rizwan ( 0000-0003-0449-1559 ) ; Hallani, Rawad K.; Jarolimek, Karol; Day, Cynthia S.; Risko, Chad; Anthony, John E.; Amassian, Aram ( 0000-0002-5734-1194 ) ; Jurchescu, Oana D. ( 0000-0003-2204-2909 )
Abstract:
The temperature dependence of the charge-carrier mobility provides essential insight into the charge transport mechanisms in organic semiconductors. Such knowledge imparts critical understanding of the electrical properties of these materials, leading to better design of high-performance materials for consumer applications. Here, we present experimental results that suggest that the inhomogeneous strain induced in organic semiconductor layers by the mismatch between the coefficients of thermal expansion (CTE) of the consecutive device layers of field-effect transistors generates trapping states that localize charge carriers. We observe a universal scaling between the activation energy of the transistors and the interfacial thermal expansion mismatch, in which band-like transport is observed for similar CTEs, and activated transport otherwise. Our results provide evidence that a high-quality semiconductor layer is necessary, but not sufficient, to obtain efficient charge-carrier transport in devices, and underline the importance of holistic device design to achieve the intrinsic performance limits of a given organic semiconductor. We go on to show that insertion of an ultrathin CTE buffer layer mitigates this problem and can help achieve band-like transport on a wide range of substrate platforms.
KAUST Department:
KAUST Solar Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia.; Physical Sciences and Engineering (PSE) Division
Citation:
Mei Y, Diemer PJ, Niazi MR, Hallani RK, Jarolimek K, et al. (2017) Crossover from band-like to thermally activated charge transport in organic transistors due to strain-induced traps. Proceedings of the National Academy of Sciences: 201705164. Available: http://dx.doi.org/10.1073/pnas.1705164114.
Publisher:
Proceedings of the National Academy of Sciences
Journal:
Proceedings of the National Academy of Sciences
Issue Date:
2-Aug-2017
DOI:
10.1073/pnas.1705164114
Type:
Article
ISSN:
0027-8424; 1091-6490
Sponsors:
J.E.A. and C.R. thank the National Science Foundation (DMR-1627428) for support of calculations and organic semiconductor synthesis. The device work at Wake Forest was supported by the National Science Foundation under Grants ECCS-1254757 and DMR-1627925.
Additional Links:
http://www.pnas.org/content/early/2017/07/20/1705164114.full
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorMei, Yaochuanen
dc.contributor.authorDiemer, Peter J.en
dc.contributor.authorNiazi, Muhammad Rizwanen
dc.contributor.authorHallani, Rawad K.en
dc.contributor.authorJarolimek, Karolen
dc.contributor.authorDay, Cynthia S.en
dc.contributor.authorRisko, Chaden
dc.contributor.authorAnthony, John E.en
dc.contributor.authorAmassian, Aramen
dc.contributor.authorJurchescu, Oana D.en
dc.date.accessioned2017-08-14T06:41:37Z-
dc.date.available2017-08-14T06:41:37Z-
dc.date.issued2017-08-02en
dc.identifier.citationMei Y, Diemer PJ, Niazi MR, Hallani RK, Jarolimek K, et al. (2017) Crossover from band-like to thermally activated charge transport in organic transistors due to strain-induced traps. Proceedings of the National Academy of Sciences: 201705164. Available: http://dx.doi.org/10.1073/pnas.1705164114.en
dc.identifier.issn0027-8424en
dc.identifier.issn1091-6490en
dc.identifier.doi10.1073/pnas.1705164114en
dc.identifier.urihttp://hdl.handle.net/10754/625330-
dc.description.abstractThe temperature dependence of the charge-carrier mobility provides essential insight into the charge transport mechanisms in organic semiconductors. Such knowledge imparts critical understanding of the electrical properties of these materials, leading to better design of high-performance materials for consumer applications. Here, we present experimental results that suggest that the inhomogeneous strain induced in organic semiconductor layers by the mismatch between the coefficients of thermal expansion (CTE) of the consecutive device layers of field-effect transistors generates trapping states that localize charge carriers. We observe a universal scaling between the activation energy of the transistors and the interfacial thermal expansion mismatch, in which band-like transport is observed for similar CTEs, and activated transport otherwise. Our results provide evidence that a high-quality semiconductor layer is necessary, but not sufficient, to obtain efficient charge-carrier transport in devices, and underline the importance of holistic device design to achieve the intrinsic performance limits of a given organic semiconductor. We go on to show that insertion of an ultrathin CTE buffer layer mitigates this problem and can help achieve band-like transport on a wide range of substrate platforms.en
dc.description.sponsorshipJ.E.A. and C.R. thank the National Science Foundation (DMR-1627428) for support of calculations and organic semiconductor synthesis. The device work at Wake Forest was supported by the National Science Foundation under Grants ECCS-1254757 and DMR-1627925.en
dc.publisherProceedings of the National Academy of Sciencesen
dc.relation.urlhttp://www.pnas.org/content/early/2017/07/20/1705164114.fullen
dc.rightsArchived with thanks to Proceedings of the National Academy of Sciencesen
dc.subjectOrganic Semiconductorsen
dc.subjectOrganic Field-effect Transistorsen
dc.subjectOrganic Devicesen
dc.subjectCharge-carrier Mobilityen
dc.subjectElectronic Trapsen
dc.titleCrossover from band-like to thermally activated charge transport in organic transistors due to strain-induced trapsen
dc.typeArticleen
dc.contributor.departmentKAUST Solar Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia.en
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalProceedings of the National Academy of Sciencesen
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.institutionDepartment of Physics, Wake Forest University, Winston-Salem, NC 27109.en
dc.contributor.institutionDepartment of Chemistry and Center for Applied Energy Research, University of Kentucky, Lexington, KY 40506.en
dc.contributor.institutionDepartment of Chemistry, Wake Forest University, Winston-Salem, NC 27109.en
kaust.authorNiazi, Muhammad Rizwanen
kaust.authorNiazi, Muhammad Rizwanen
kaust.authorAmassian, Aramen
kaust.authorAmassian, Aramen
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