Ambient fabrication of efficient triple cation perovskite-based near-infrared light-emitting diodes

In addition to their widespread use as an outstanding light-harvesting material, solution-based organometallic halide perovskites have also recently emerged as a promising material for light-emitting diode (LED) applications. However, their stability under an ambient environment remains a challenge. Triple cation perovskites offer an appealing solution as it reduces the sensitivity to the processing conditions and improves the purity of the perovskite films. This work describes a facile ambient-processed thiocyanate-doped triple-cation perovskite Cs-x(MA(0.17)FA(0.83))Pb(100-x)(I0.83Br0.17)(3) used for high-performance perovskite-based LEDs with peak emission at 750 nm. Using the perovskite film tailoring technique by mixing DMF (N,N-Dimethylmethanamide) with perovskite precursor, we are able to reduce the perovskite grain size and optimize the film thickness while preserving its crystalline structure. With optimized processing techniques, we achieve a similar to 90% improvement of the perovskite LEDs external quantum efficiency (EQE) from similar to 3.1% to similar to 5.9%. We believe this triple cation perovskite synthesis approach and film tailoring technique yields excellent device performances and constitutes a significant step towards low-cost and efficient LEDs. (C) 2021 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

In addition to being widely used as a excellent light-harvesting material, solution-based organometallic halide perovskites are also becoming a promising material for light-emitting diode (LED) applications. However, their stability under ambient conditions remains a challenge. Triple cation perovskites provide an attractive solution by reducing sensitivity to processing conditions and improving the purity of the perovskite films.