Room temperature synthesis of perovskite for stable light-emitting diodes by tin doping and organic ligand

Abstract

Halide perovskites have attracted great attention for optoelectronic applications owing to their high photoluminescence quantum yield (PLQY), tunable bandgap, and simple processing. However, poor stability and defect-induced nonradiative recombination hinder their practical use in perovskite light-emitting diodes (PeLEDs). Here, we demonstrate a synergistic strategy combining tin (Sn) doping and dopamine hydrochloride (DH) incorporation via a ligand-assisted reprecipitation (LARP) process to achieve stable perovskite films under ambient conditions. Coordination between the amine and carbonyl groups in DH and metal ions effectively suppresses Sn2+ oxidation and Pb° formation, leading to controlled surface defect densities and enhanced crystallinity. The optimized Sn:DH perovskite showed an improved average photoluminescence (PL) lifetime and retained 63% PLQY after 144 h, which is close to the initial value of 65%. PeLEDs fabricated with Sn:DH films exhibit a maximum luminance of 9,522 cd m-2, approximately twice that of the pristine devices, and an extended operational T50 of 123 min. This dual-additive-assisted approach offers a simple and scalable pathway to produce defect-stable perovskite emitters with improved durability and optoelectronic performance for next-generation PeLED technologies.