Synthesis of $CsPbBr_3$ perovskite nanocrystals for blue light emission with high photoluminescence quantum yield

Abstract

Humans get the most information through vision when they grasp information about an object. Therefore, the display plays an important role in the components of the device that can obtain various information. Perovskite's defect tolerance properties allow high color purity to be emitted with a narrow emission spectrum of less than 20 nm. Perovskite has attracted attention as the next generation of display materials, with external quantum efficiencies of 21.3% and 20.3% for red and green devices, respectively, over the last six years. However, blue devices are still under 1% of external quantum efficiency. In this study, the nanoparticles of perovskite were synthesized for high-efficiency blue light emission and the photoluminescence quantum yield was improved through surface treatment. Low dimensional $CsPbBr_3$ perovskite nanoplatelets were synthesized to increase exciton binding energy. By varying the ratio of Cs and $PbBr_2$ precursors, the thickness of the nanoplatelets was uniformly adjusted to obtain various blue emission wavelength. The post-treatment using tetrafluoroborate salt prevented the efficiency decrease due to surface defects, thereby achieving a luminescence efficiency of 63% at the blue light emission wavelength of 457 nm.