The synthesis and characterisation of the highly stable perovskite nano crystals and their application to ink-jet printed colour conversion layers

We synthesised cesium lead bromide and formamidinium lead bromide perovskite colloidal nanocrystals by ligand-assisted reprecipitation method for the wide-colour gamut low-cost displays. The prepared perovskite colloidal nanocrystal solutions were formulated into the ink-jet printable homogeneous inks and uniformly coated as the colour conversion layers of the quantum dot organic light-emitting diode displays. The silica capped CsPbBr3 nanocrystals were very stable in high temperature observation while the FAPbBr(3) showed the excellent long-term stability at room temperature even without the silica passivation. The ink-jet printed colour conversion films had very narrow full-width-at-half-maximums of around 20 nm and high photoluminescence quantum yields of 73.0% and 76.9%, respectively. Particularly, the FAPbBr(3) thin film had an excellent cut-off ratio of blue emission and exhibited external quantum efficiency of 5.39% when fabricated as the hybrid display devices. (C) 2020 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.