Enabling Quasi-2D Perovskite-Compatible Growth Environment for Efficient Light-Emitting Diodes

Despite the rapid advancement in electroluminescence efficiencies of perovskite light-emitting diodes (PeLEDs), it remains challenging to achieve efficient and reproducible devices. Herein, an effective vapor-assisted growth (VAG) method is proposed to develop quasi-2D perovskite thin-films via creating a saturated dimethyl sulfoxide vapor environment. The VAG-optimized perovskite films with a composition of PEA(2)(FAPbBr(3))(n)-1PbBr4 display uniformly distributed nanograins with graded energy landscape and compact surface, contributing to enhanced radiative and suppressed nonradiative recombination. Consequently, the PeLEDs incorporating VAG-based films with a device architecture of indium tin oxide/poly(9,9-dioctylfluorene-alt-N-(4-sec-butylphenyl)-diphenylamine)/perovskite/(1,3,5-tris(phenyl-2-benzimidazolyl)benzene)/Yb/Ag demonstrate a peak current efficiency of 27.1 cd A(-1) (@ 532 nm) with an external quantum efficiency of 6.50% and a maximum luminance of 17 610 cd m(-2). Notably, champion PeLEDs manifest considerably curtailed efficiency roll-off as approximate to 50% of the peak efficiency is preserved even at a very high luminance of 15 000 cd m(-2). Meanwhile, VAG-based PeLEDs exhibit improved reproducibility compared to the control counterparts. It is anticipated that this work would promote the development of reliable solution-processing methods toward stabilized perovskite-based photonics.