PUBLICATIONS

Advanced Devices for Energy Conversion

Journals

Nature Communications
년도 2020
학술지명 Nature Communications
논문명 The role of photon recycling in perovskite light-emitting diodes
게재권/집 11/30
수록페이지 611
저자명 Changsoon Cho, Baodan Zhao, Gregory Tainter, Jung-Yong Lee, Richard Friend, Dawei Di*, Felix Deschler*, and Neil Greenham*
Link 관련링크 https://doi.org/10.1038/s41467-020-14401-1 4146회 연결

Abstract


Perovskite light-emitting diodes have recently broken the 20% barrier for external quantum efficiency. These values cannot be explained with classical models for optical outcoupling. Here, we analyse the role of photon recycling (PR) in assisting light extraction from perovskite light-emitting diodes. Spatially-resolved photoluminescence and electroluminescence measurements combined with optical modelling show that repetitive re-absorption and re-emission of photons trapped in substrate and waveguide modes significantly enhance light extraction when the radiation efficiency is sufficiently high. In this manner, PR can contribute more than 70% to the overall emission, in agreement with recently-reported high efficiencies. While an outcoupling efficiency of 100% is theoretically possible with PR, parasitic absorption losses due to absorption from the electrodes are shown to limit practical efficiencies in current device architectures. To overcome the present limits, we propose a future configuration with a reduced injection electrode area to drive the efficiency toward 100%.