The Polymer Society of Korea

Abstract

Perovskites are gaining attention as promising materials for next-generation optoelectronic devices, particularly in solar cells and light-emitting diodes (LEDs), due to their high performance and optical properties. Perovskite LEDs have been optimized to achieve external quantum efficiencies over 20%. Unlike organic light emitters, perovskites have high refractive indices (n > 2), leading to a low theoretical light extraction limit of 1/2n² (<12%). However, recent experimental results show efficiencies much higher than this limit. This discrepancy is mainly due to the photon recycling effect, where reabsorbed photons in trapped optical modes are reemitted, in addition to the microcavity effect. This study investigates the role of photon recycling in enhancing perovskite LED performance by quantifying external efficiencies. We propose an optical model that includes emitter reabsorption, offering design guidelines for efficient perovskite LEDs, distinct from organic LEDs.