ZnF2 modulation of a CsPbBr3@glass composite: a heat treatment-free approach to reach stable and bright green emission for backlight display devices

The unique combination of perovskite nanocrystals (PeNCs) and glass matrices offers a platform for the development of advanced optoelectronic materials with tailored luminescence characteristics, high quantum efficiency, and tunable emission wavelengths, along with exceptional stability against degradation. Herein, we successfully fabricated CsPbBr₃ perovskite@glass (PeG) composites with excellent stability and optical properties by optimizing the precipitation conditions of the PeNCs. It was found that the addition of ZnF₂ enhances the precipitation of PeNCs due to its etching effect while simultaneously reducing the activation energy for glass crystallization. This eliminated the need for the commonly used secondary heat-treatments during the glass fabrication process. The optimized composition exhibited bright green emission with a high photoluminescence quantum yield (PLQY) of 91%, narrow emission profiles of less than 30 nm, and average decay lifetimes of ∼11 ns. The strong protecting effect of the glass matrix on the luminescence characteristics of the PeNCs was also confirmed after one month of soaking in water. Furthermore, the ZnF₂-doped PeG composites were dual-encapsulated via a polydimethylsiloxane (PDMS) polymer, and their potential ability in backlight displays was tested. The scalable, heat-treatment-free method, along with bright and durable emission, makes this novel composition ideal for practical applications like display pixels.