Aluminum Carboxylate Modification Enabled Efficient and Stable Perovskite-Polystyrene Thin Films for Light-Emitting Applications.

Lead halide perovskite nanocrystals (PNCs) have demonstrated great potential in emerging display technologies. However, the practical application of PNCs is hindered by the inherent instability of their ionic surface. Here, we proposed a surface modification approach to enhance the stability of CsPbBr 3 PNCs by postsynthetic treatment with aluminum phenylbutyrate (Al(PA) 3 ). Our study reveals that Al(PA) 3 displaces ammonium ligands and binds tightly on surface halide, providing excellent air and moisture resistance while preserving a high quantum efficiency of 81.6%. The modified PNCs maintain a constant photoluminescence intensity under continuous UV light illumination for 500 h. Additionally, the Al(PA) 3 ligand is compatible with styrene, enabling homogeneous dispersion of PNCs in polystyrene matrices to form bright and uniform PNC-PS thin films. We demonstrated the application of the composite films for display backlighting, which exhibits a wide color gamut of 125% NTSC. The result highlights the potential of AlPA-modified PNCs in light-emitting and other optoelectronic devices.