Halide perovskite based light-emitting diodes: a scaling up perspective

Abstract

Metal halide perovskite light-emitting diodes (PeLEDs) have aroused extensive attention due to their high color purity, wide color gamut, and low-cost solution processability, showing great potential for application in next-generation high-definition display and solid-state lighting. Recently, the external quantum efficiencies (EQEs) for PeLEDs have impressively exceeded 20%; however, they were all achieved in laboratory-scale devices (<0.1 cm²). With scaling up device area, the efficiency will be reduced dramatically by the non-uniformity of large-area perovskite layers because the generated pinholes or cracks increase defect-induced nonradiative recombination and lead to current leakage. The development of large-area PeLEDs (≥1 cm²) is challenged by the difficulty in preparing dense and uniform perovskite thin films on large scale. In this Perspective, we briefly introduce the basic features of perovskite materials and systematically summarize the fabrication technologies for large-area perovskite films; we then present the recent advances in large-area PeLEDs. Finally, the challenges and opportunities for further enlarging the active emission area of PeLEDs are discussed.