Ultra-narrowband emitting and highly stable CsPbX3@glass@PDMS (X3=Br3, Br1.5I1.5) monolithic composite film for backlit displays

Perovskite quantum dots are considered an ideal alternative to traditional phosphor color converters because of their excellent optical properties. However, the bottleneck problem of instability has tremendously limited their practical applications. In the present work, we fabricate green-emitting CsPbBr3@glass and red-emitting CsPbBr1.5I1.5@glass nanocomposites via an in-situ nucleation/growth method. Importantly, the CsPbX3@glass (X3 = Br3, Br1.5I1.5) samples exhibit striking thermal reversibility in the heating/cooling cycle experiments. Furthermore, CsPbX3 monolithic films with high photoluminescence quantum yields (PLQYs) of 80–95% and narrow full-width at half-maximum (FWHM) down to 16 nm are achieved by dispersing ground CsPbX3@glass particles in polydimethylsiloxane (PDMS) matrix. Benefiting from dual encapsulation of inorganic glass matrix and organic polymer matrix, the film can endure harsh accelerated aging tests (at 85 °C/85%RH for 500 h). Finally, combining the as-prepared yellow monolithic film with blue chips as the backlight endows the liquid crystal display (LCD) with a wide color gamut (a color gamut of 146% of commercial LCD, 101% of NTSC after passing the color filters), demonstrating great prospects in the display industry.