Ultra-High Brightness Near-Infrared Perovskite Light-Emitting Diodes Enabled by Aluminum-Doped Zinc Oxide Electron Transport Layers

Abstract

Near-infrared (NIR) perovskite light-emitting diodes (PeLEDs) have achieved substantial gains in quantum efficiency, yet their limited brightness remains a significant constraint for practical deployment. Here, we demonstrate a highly efficient approach to enhancing NIR PeLEDs' brightness by incorporating a solution-processed aluminum-doped zinc oxide (AZO) electron transport layer (ETL). Systematic structural, optical, and electronic characterizations reveal that AZO enables improved electron transport properties, better energy-level alignment, and enhanced charge injection dynamics. As a result, AZO-integrated FAPbI3 PeLEDs exhibit an outstanding brightness of 3313.9 W sr⁻¹ m⁻², a 146% increase over reference devices. Electrochemical impedance spectroscopy (EIS) further confirms a substantially lower charge transfer resistance (1178.02 Ω) and reduced surface charge recombination resistance (397.11 Ω), indicating more efficient carrier transport and recombination. This work provides a scalable and effective strategy to overcome brightness limitations in NIR PeLEDs, advancing their potential for high-intensity optoelectronic applications, including next-generation display technologies and NIR light sources.