One-step spray coating strategy toward a highly uniform large-area CsPbBr₃@PMMA composite film for backlit display

The large-scale and continuous production of CsPbBr₃@PMMA composite film is realized by the in-situ ultrasonic spray coating method at room temperature. Through embedding CsPbBr₃ nanocrystals into the hydrophobic polymer framework, the as-fabricated films (20 cm × 20 cm) exhibit uniform green emissions with a relatively high PLQYs of 76%, and could maintain 80% PL intensity after 3 months storage under ambient conditions. Assembling the green-emissive CsPbBr₃@PMMA film and the red-emissive KSF@PMMA film with blue LED chip, a high-performance LCD is obtained, reaching a higher saturation with 126% and 94% color gamut of NTSC and Rec.2020, respectively. This work demonstrates that ultrasonic spray coating technique could be widely used in the large-scale fabrication of uniformly high-quality perovskite films for backlight application.