Identifying Key Properties of Electrolytes for Light-Emitting Electrochemical Cells
2014 (English)In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 26, no 17, 5083-5088 p.Article in journal (Refereed) Published
The electrolyte is a key component in light-emitting electrochemical cells (LECs), as it facilitates in situ electrochemical doping and associated attractive device features. LiCF3SO3 dissolved in hydroxyl-capped trimethylolpropane ethoxylate (TMPE-OH) constitutes an electrolyte with which we have attained high stability and efficiency for polymer LECs, but the turn-on time of such devices is unfortunately slow. By replacing hydroxyl with methoxy as the TMPE end-group, we produced LECs with a desired combination of high efficiency, good stability, and fast turn-on time. Specifically, we showed that the turn-on time to high luminance (300 cd/m(2)) at a current density of 7.7 mA/cm(2) is lowered from 1740 to 16 s, that the efficiency is improved by similar to 20%, and that the other device properties are either maintained or improved. In a parallel modeling and experimental effort, we demonstrated that the faster kinetics following the shift in the TMPE end-group is attributed to a marked decrease in the level of both inter- and intramolecular interactions of the electrolyte, as manifested in a lowered electrolyte viscosity, faster ion transport, and more facile ion release during doping.
Place, publisher, year, edition, pages
American Chemical Society (ACS), 2014. Vol. 26, no 17, 5083-5088 p.
Physical Sciences Chemical Sciences
IdentifiersURN: urn:nbn:se:umu:diva-94948DOI: 10.1021/cm5022905ISI: 000341543200025OAI: oai:DiVA.org:umu-94948DiVA: diva2:758930