Controllable synthesis of blue-emitting CsPbBr3 nanoplates via a SnBr2-mediated solvothermal reaction method

Abstract

Blue-emitting CsPbX3 (X = Cl, Br, I) nanocrystals (NCs) have potential applications in white light illumination and full-color luminescent displays. However, current methods for synthesizing blue-emitting CsPbX3 NCs face challenges in poor controllability, low photoluminescence quantum yields (PLQYs), and the harmful effects of short-wavelength blue light. In this work, we report on a SnBr2-mediated solvothermal method for the controllable synthesis of blue-emitting CsPbBr3 nanoplates (NPLs) that exhibit high optical purity within the harmless blue light range. The pioneering use of SnBr2 as a mediator in solvothermal reactions plays a crucial role in the controllable synthesis process. By increasing the amount of SnBr2, the as-prepared products gradually transform from CsPbBr3 NCs to mixed CsPbBr3/Cs4PbBr6 NCs, and finally to CsPbBr3 NPLs. By further adjusting the solvothermal reaction conditions, CsPbBr3 NPLs with controlled thickness (2.34–3.53 nm), regulated blue-light emission (459.4–466.6 nm) and a high PLQY up to 63.17% can be obtained. This study provides a feasible method for the controllable synthesis of perovskite NPLs and opens up new possibilities for the application of perovskite blue light-emitting devices.