A New Transparent Organic Glass with Unity Photoluminescence Quantum Yield

Transparent meltable glasses are keenly desired for making color‐conversion layer of Mini‐LEDs. In this work, transparent luminescent organic glasses were prepared using a new matrix of heptyltriphenylphosphonium bromide (C 25 H 30 BrP, HTPBr). Through doping of a blue dye (9,10‐diphenylanthracene, DPA), the resulting glass exhibited a high transparency (92%) and a blue emission at 436 nm. Importantly, the PL QY of glass reached up to nearly unity under 398‐nm excitation. X‐ray diffraction (XRD) measurement confirmed the amorphous nature of the glass. Thermal characterization revealed a glass transition temperature (T g ) of 28 °C, a melting temperature (T m ) of 178 °C, and a thermal decomposition temperature of 270 °C. Apart from the blue‐emitting glass, green‐ and red‐emitting glasses of high transparency were synthesized varied chromophores, including 9,10‐bis(phenylethynyl)anthracene (BPEA) and rhodamine B. In a proof‐of‐concept experiment, these glasses were used to encapsulate UV LEDs via a simple dipping process, which showed a satisfactory color rendering ability. This work brought a new member into the family of transparent luminescent glasses, promising many applications in areas including full‐color displays and large‐area mini‐LED panels.