Controlling the Emission Zone by Additives for Improved Light-Emitting Electrochemical CellsShow others and affiliations
2022 (English)In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 34, no 8, article id 2107849Article in journal (Refereed) Published
Abstract [en]
The position of the emission zone (EZ) in the active material of a light-emitting electrochemical cell (LEC) has a profound influence on its performance because of microcavity effects and doping- and electrode-induced quenching. Previous attempts of EZ control have focused on the two principal constituents in the active material—the organic semiconductor (OSC) and the mobile ions—but this study demonstrates that it is possible to effectively control the EZ position through the inclusion of an appropriate additive into the active material. More specifically, it is shown that a mere modification of the end group on an added neutral compound, which also functions as an ion transporter, results in a shifted EZ from close to the anode to the center of the active material, which translates into a 60% improvement of the power efficiency. This particular finding is rationalized by a lowering of the effective electron mobility of the OSC through specific additive: OSC interactions, but the more important generic conclusion is that it is possible to control the EZ position, and thereby the LEC performance, by the straightforward inclusion of an easily tuned additive in the active material. © 2022 The Authors.
Place, publisher, year, edition, pages
John Wiley and Sons Inc , 2022. Vol. 34, no 8, article id 2107849
Keywords [en]
Electrodes, Light emission, Semiconductor doping, Active material, Emission zone, End groups, Ion transporters, Light-emitting electrochemical cell, Microcavity effects, Mobile ions, Neutral compounds, Performance, Zone controls, Electrochemical cells
National Category
Condensed Matter Physics
Identifiers
URN: urn:nbn:se:ri:diva-58440DOI: 10.1002/adma.202107849Scopus ID: 2-s2.0-85122826739OAI: oai:DiVA.org:ri-58440DiVA, id: diva2:1633481
Note
Funding details: Bertil and Britt Svenssons Stiftelse för Belysningsteknik; Funding details: Wenner-Gren Stiftelserna; Funding details: Stiftelsen för Strategisk Forskning, SSF; Funding details: Stiftelsen Olle Engkvist Byggmästare; Funding details: Vetenskapsrådet, VR; Funding details: Energimyndigheten; Funding details: Kempestiftelserna; Funding text 1: The authors gratefully acknowledge Andreas Poehlmann for the development of the open‐source python‐seabreeze library for the control of the Ocean Optics spectrometer, and Mikael Fredriksson at Umeå University for his contribution to the 3D printing of the spectrogoniometer setup. The authors also gratefully acknowledge the reviewers for their constructive input, which helped them improve the clarity and quality of the manuscript. The authors finally acknowledge generous financial support from Kempestiftelserna, the Swedish Research Council, the Swedish Energy Agency, the Swedish Foundation for Strategic Research, Stiftelsen Olle Engkvist Byggmästare, Wenner‐Gren Foundations, and Bertil and Britt Svenssons stiftelse för belysningsteknik.
2022-01-312022-01-312022-07-22Bibliographically approved