Low thermal quenching of metal halide based metal–organic framework phosphor for light-emitting diodes

Abstract

Phosphor-converted white light-emitting diodes (PC-WLEDs) have attracted considerable attention in the fields of solid-state lighting and display. However, urgent issues of thermal quenching and high-cost still remain formidable challenge. Herein, a novel metal–organic framework (MOF) phosphor [CdCl2(AD)] can be facilely prepared by the mixture of CdCl2 and acridine (AD) under a solvothermal condition. It shows intensive green emission with long lifetime of 31.88 ns and quantum yield of 65%, maintains 95% and 84% of its initial emission intensity after immersed in water for 60 days and heated to 150 °C, respectively. The low thermal quenching of this MOF material can be compared to or even exceed that of commercial inorganic phosphors. The combination of experiments and theoretical calculations reveals that the alternating arrangement of the delocalized AD π-conjugated system and CdCl2 inorganic chains through strong coordination bonds and π···π stacking interactions enable the MOF phosphor high thermal stability and optoelectronic performance. The successful fabrication of green and white LED devices by coating [CdCl2(AD)] and/or N630 red phosphor on a 365/460 nm commercial diode chip suggests a promising and potential alternative to commercial phosphors.