Ultrathin silica-encapsulated perovskite nanocrystals for high color purity mechanoluminescence

The quest for advanced mechanoluminescence (ML) systems with precise color control and a broad color gamut is pivotal for developing flexible display technologies. Despite significant progress in embedding ML phosphors into elastic polymer matrices to enhance flexibility and resilience, achieving high color purity and a broad color spectrum remains a substantial challenge. This study introduces an innovative approach by incorporating ultrathin silica-encapsulated perovskite nanocrystals (PNCs) into the ML platform, leveraging their exceptional color purity and high photoluminescence quantum yield. Our encapsulation technique, which covers PNCs with SiO2 shells, not only enhances the environmental stability of PNCs but also enables their integration into a polydimethylsiloxane (PDMS)-based ML matrix, thereby forming a robust perovskite mechanoluminescence platform (PMP) film. This strategy significantly improves ML color purity with a full width at half maximum (FWHM) of 32 nm, as well as leading to high ML stability in various harsh conditions such as heating and water immersion. Our findings demonstrate the potential of silica-encapsulated PNCs to transcend the conventional limitations of ML systems, marking a significant stride towards the realization of advanced flexible displays with superior color purity.