Effective Stabilization of Perovskite Cesium Lead Bromide Nanocrystals through Facile Surface Modification by Perfluorocarbon Acid

摘要

CsPbX3 (X = Cl, Br, I) perovskite nanocrystals (NCs) have attracted much attention as promising materials for next-generation optoelectronic applications. However, improvement of their low stabilities against heating and humidity is needed for practical use. In this work, we focused on perfluorodecanoic acid (PFDA) as a surface ligand and investigated the thermal and chemical stabilities of the photoluminescence (PL) properties of CsPbBr3 NCs. Oleic acid (OA) adsorbed on the NCs was exchanged for decanoic acid (DA) and PFDA. OA-modified and DA-modified NCs exhibited drastic fluorescence quenching to 12.9 and 21.1% of their initial PL intensities, respectively, after heating at 100 °C for 4 h. In contrast, the PFDA-modified NCs maintained 92.1% of their PL intensity after the same heating. Furthermore, the polar solvent resistance was also improved by PFDA modification. These improvements can be attributed to the strong adsorptivity and high chemical stability of the PFDA ligand.