Synthesis of the beyond quantum size perovskite nanoparticles and their application to light-emitting diodes

Abstract

For the last decade, many studies have been conducted on organic-inorganic perovskite quantum dots (QDs) as next-generation light-emitting materials due to their high color purity and easy color tunability. However, these 10nm-sized perovskite QDs which are similar in size to perovskite’s exciton Bohr radius are influenced by a strong quantum confinement effect. The Quantum confinement effect leads to the change of perovskite QDs’ bandgap and emission wavelength. Furthermore, their size distribution gives rise to broad of perovskite’s full width at half maximum (FWHM) in photoluminescence (PL) spectra and offsets the advantages of perovskite light-emitting diode (LED) in terms of high color purity. Here, we report a method of synthesizing perovskite nanoparticles that are not affected by quantum confinement effects by controlling their size through the modified ligand-assisted reprecipitation (LARP) method. Nanoparticles showed narrow FWHM (~18.7 nm) with high photoluminescence quantum efficiency (PLQY) (~86.3%). Moreover, we fabricated the high color purity of LED by introducing the nanoparticles-polymer structure (Host-Guest) with narrow FWHM (~20 nm).