Reducing Thermal Quenching in Dye@MOF/BN Phosphors for Highly‐Efficient White Light Emitting Diodes (WLEDs)

Abstract Although dye‐encapsulated metal‐organic framework (dye@MOF) phosphors exhibit excellent advantages (e.g., high quantum yield (QY) and luminescence tunability) in white light emitting diodes (WLEDs) lighting, the considerable fluorescence quenching of these dye@MOF phosphors remains an unmet challenge due to their low thermal conductivity and strong thermal accumulation. In this research, a high QY dye@MOF phosphor (QY = 78.4%) is successfully prepared using the secondary growth method. Through in situ doping of hexagonal boron nitride (BN), a yellow phosphor dye@MOF/BN is synthesized to mitigate thermal quenching and improve phosphor stability in WLEDs. The WLEDs constructed with 450 nm blue LED chips exhibit a temperature reduction of 10.2 °C at a current of 10 mA after continuous operation for 8 hours, compared to those fabricated by pristine phosphor. The dye@MOF/BN based WLEDs maintain high performance with a luminous efficacy of 93.89 lm W⁻¹, color rendering index of 86.4, and QY of 64.4%, indicating that the proposed strategy effectively improves heat dissipation without compromising optical performance.