High Efficiency Blue and Green Light-Emitting Diodes Using Ruddlesden–Popper Inorganic Mixed Halide Perovskites with Butylammonium Interlayers

By Parth Vashishtha, Michael Ng, S. B. Shivarudraiah, J. Halpert. Chemistry of Materials, 2018

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Ruddlesden–Popper phase inorganic metal halide perovskites are promising candidates for efficient light-emitting diodes (LEDs) with high brightness and color purity. Here, we demonstrate LEDs made from in situ grown CsPbX3 quasi 2D/3D thin films that are color tunable across the entire visible spectrum. CsPbX3 nanosheets are used to produce RP phase perovskites using butylammonium as a separating ligand to create BA2Csn–1Pbn(Br/Y)3n+1 2D/3D mixed halide thin films, where Y = Cl or I. The number of CsPbBr3 monolayers in these crystals was optimized by changing the butylammonium concentration. We demonstrate a stable perovskite phase with thin emission line widths providing points covering the edge of the CIE triangle and a maximum red/green/blue coverage of ∼130% of the National Television System Committee color standard. Additionally, we are able to report record efficiencies for blue emitting perovskite nanocrystal LEDs with a maximum external quantum efficiency (EQE) of 2.4% and 6.2% at 465 and 487 nm a...

Subfields: Electrical and Electronic Engineering, Materials Chemistry, Social Psychology

View Paper: https://www.semanticscholar.org/paper/ee03b1b874e0faa41ed3d988924df34423774728