Large area perovskite light-emitting diodes by gas-assisted crystallization

Abstract

Halide perovskites have been gaining considerable attention recently for use in light-emitting applications, due to their bandgap tunability, color purity and low cost fabrication methods. However, current fabrication techniques limit the processing to small-area devices. Here, we show that a facile N₂ gas-quenching technique can be used to make methylammonium lead bromide-based perovskite light-emitting diodes (PeLEDs) with a peak luminance of 6600 cd m⁻² and a current efficiency of 7.0 cd A⁻¹. We use this strategy to upscale PeLEDs to large-area substrates (230 cm²) by developing a protocol for slot-die coating combined with gas-quenching. The resulting large area devices (9 devices of each 4.46 cm² per substrate) with three slot-die coated layers exhibit uniform emission with a peak luminance of 550 cd m⁻² and a current efficiency of 2.6 cd A⁻¹. The reasons for the reduced performance and improvement routes are discussed. These results mark a vital step towards scalable manufacturing techniques for PeLEDs.