Efficient and Spectrally Stable Blue Perovskite Light-Emitting Diodes Employing a Cationic π-Conjugated Polymer.

Authors
Yuan, Shuai 
Dai, Linjie 
Liu, Yun 
Liu, Qing-Wei 

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Article
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Abstract

Metal halide perovskite semiconductors have demonstrated remarkable potentials in solution-processed blue light-emitting diodes (LEDs). However, the unsatisfied efficiency and spectral stability responsible for trap-mediated non-radiative losses and halide phase segregation remain the primary unsolved challenges for blue perovskite LEDs. In this study, it is reported that a fluorene-based π-conjugated cationic polymer can be blended with the perovskite semiconductor to control film formation and optoelectronic properties. As a result, sky-blue and true-blue perovskite LEDs with Commission Internationale de l'Eclairage coordinates of (0.08, 0.22) and (0.12, 0.13) at the record external quantum efficiencies of 11.2% and 8.0% were achieved. In addition, the mixed halide perovskites with the conjugated cationic polymer exhibit excellent spectral stability under external bias. This result illustrates that π-conjugated cationic polymers have a great potential to realize efficient blue mixed-halide perovskite LEDs with stable electroluminescence.

Publication Date
2021-11
Online Publication Date
2021-09-24
Acceptance Date
2021-08-24
Keywords
blue emissions, high efficiencies, ion migrations, perovskite light-emitting diodes, stabilities
Journal Title
Advanced Materials
Journal ISSN
0935-9648
1521-4095
Volume Title
33
Publisher
Wiley
Sponsorship
Royal Society (UF150033)
European Research Council (756962)
European Commission Horizon 2020 (H2020) Marie Sk?odowska-Curie actions (841386)
Engineering and Physical Sciences Research Council (EP/M005143/1)
Engineering and Physical Sciences Research Council (EP/M01083X/1)
European Research Council (670405)
Engineering and Physical Sciences Research Council (EPSRC) for funding (EP/M01083X/1, EP/M005143/1)