Author:
Huseynova Gunel,Ràfols-Ribé Joan,Auroux Etienne,Huang Ping,Tang Shi,Larsen Christian,Edman Ludvig
Abstract
AbstractThe initial operation of a light-emitting electrochemical cell (LEC) constitutes the in-situ formation of a p–n junction doping structure in the active material by electrochemical doping. It has been firmly established that the spatial position of the emissive p–n junction in the interelectrode gap has a profound influence on the LEC performance because of exciton quenching and microcavity effects. Hence, practical strategies for a control of the position of the p–n junction in LEC devices are highly desired. Here, we introduce a “chemical pre-doping” approach for the rational shifting of the p–n junction for improved performance. Specifically, we demonstrate, by combined experiments and simulations, that the addition of a strong chemical reductant termed “reduced benzyl viologen” to a common active-material ink during LEC fabrication results in a filling of deep electron traps and an associated shifting of the emissive p–n junction from the center of the active material towards the positive anode. We finally demonstrate that this chemical pre-doping approach can improve the emission efficiency and stability of a common LEC device.
Funder
Carl Tryggers Stiftelse för Vetenskaplig Forskning
Kempestiftelserna
Vetenskapsrådet
Energimyndigheten
Stiftelsen Olle Engkvist Byggmästare
Bertil och Britt Svenssons stiftelse för belysningsteknik
Wallenberg Initiative Materials Science for Sustainability
Umea University
Publisher
Springer Science and Business Media LLC