Understanding and minimizing non-radiative recombination losses in perovskite light-emitting diodes

Abstract

Light-emitting diodes (LEDs) based on metal halide perovskites have shown great promise for next-generation display technology as they offer high color purity, satisfy Rec. 2020, and have low-cost solution processability. Moreover, metal halide perovskites exhibit extraordinary optoelectronic properties such as high photoluminescence quantum yields (PLQYs), feasible spectral tunability, narrow emission and high charge-carrier mobility, which has led to a rapid increase in the external quantum efficiencies (EQEs) of up to 28% for perovskite light-emitting diodes (PeLEDs) over the past few years. Nevertheless, further increase in efficiency is impeded in these state-of-the-art devices due to the presence of non-radiative recombination losses, which also limits their operational stability. In this review, we provide a fundamental analysis of the predominant pathways that induce non-radiative recombination losses in PeLEDs, followed by a discussion on what and how reliable characterization techniques could be used to evaluate such losses. We also summarize and critically assess the most recent advances in suppressing non-radiative recombination in PeLEDs. Finally, we discuss the remaining challenges and outline future directions that aim to minimize non-radiative recombination losses and boost the efficiency of PeLEDs towards their radiative limit.