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Title [sv]
Utvecklande av rationella designkritera för en effektiv, ljusstark och miljövänlig ljus-emitterande elektrokemisk cell
Title [en]
The light-emitting electrochemical cell: Developing rational design principles for efficient, bright and green operation
Abstract [en]
The light-emitting electrochemical cell (LEC) is a novel semiconductor device that features a complex in-situ electrochemical-doping transformation during operation. Through systematic studies of its electrochemical fundamentals, we have recently been able to realize thin, flexible and light-weight LEC sheets, which are fabricated with low-cost means and which deliver large-area emission at low voltage. However, an initial optical modeling study implies that more than 80 % of the generated photons are lost within the device structure through waveguiding and self-absorption. With a combined experimental and modeling approach we now intend to identify the corresponding main culprits, establish rational design guidelines and fabricate optically efficient LECs. We will further implement a balanced host-guest approach for the attainment of a tuned doping structure, which will result in the first simultaneous delivery of strong brightness and high efficiency from an LEC. Here, the key design criteria are suppression of detrimental exciton-polaron interactions, development or identification of electrochemically stabile materials, and harvesting of triplet excitons for light emission. Finally, we will expand the practical application realm of emissive devices by replacing all rare and toxic compounds with sustainable carbon-based materials, and in the process realize LEC sheets that are environmentally sustainable during both efficient operation and during fabrication and recycling.
Publications (1 of 1) Show all publications
Enevold, J., Dahlberg, T., Stangner, T., Tang, S., Lindh, E. M., Gracia-Espino, E., . . . Edman, L. (2020). Tunable two-dimensional patterning of a semiconducting Nanometer-Thin C60 fullerene film using a spatial light modulator. ACS Applied Nano Materials, 3(6), 2574-0970
Open this publication in new window or tab >>Tunable two-dimensional patterning of a semiconducting Nanometer-Thin C60 fullerene film using a spatial light modulator
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2020 (English)In: ACS Applied Nano Materials, ISSN 2574-0970, Vol. 3, no 6, p. 2574-0970Article in journal (Other academic) Published
Abstract [en]

The photochemical coupling of fullerene molecules into covalently connected oligomeric or polymeric structures can result in drastically lowered solubility in common solvents with retained semiconductor properties. Here, we exploit this combination of properties for the utilization of fullerenes as a negative photoresist material with electronic functionality. Specifically, we develop an easily tunable exposure system, essentially comprising a laser and a computer-controlled spatial light modulator (SLM) featuring >8 million independently controlled pixels, for the spatially selective photochemical transformation of nanometer-thin C60 fullerene films. With a carefully designed laser-SLM-exposure/solvent-development cycle, we are able to realize well-resolved two-dimensional hexagonal or square patterns of circular C60 microdots with a center-to-center distance of 1–5 μm and a maximum thickness of 20–35 nm over several square-millimeter-sized areas on a substrate. The functionality of such a hexagonal C60 pattern was demonstrated by its inclusion in between the transparent electrode and the active material in a light-emitting electrochemical cell, which featured an enhanced light output by >50% in comparison to a reference device void of the patterned C60 layer.

Place, publisher, year, edition, pages
Acoustical Society of America (ASA), 2020
Keywords
C60, fullerenes, tunable and high-resolution 2D patterning, spatial light modulator, negative photoresist, light outcoupling, light-emitting electrochemical cell
National Category
Other Physics Topics
Identifiers
urn:nbn:se:umu:diva-166406 (URN)10.1021/acsanm.0c00793 (DOI)000545689000055 ()2-s2.0-85087440615 (Scopus ID)
Funder
Swedish Foundation for Strategic Research Swedish Research CouncilSwedish Energy AgencyBertil & Britt Svenssons Stiftelse för Belysningsteknik
Note

Previously included in thesis in manuscript form.

Available from: 2019-12-16 Created: 2019-12-16 Last updated: 2023-03-23Bibliographically approved
Principal InvestigatorEdman, Ludvig
Coordinating organisation
Umeå University
Funder
Period
2018-01-01 - 2021-12-31
National Category
Condensed Matter PhysicsPhysical ChemistryOther Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
DiVA, id: project:1654Project, id: 2017-04380_VR