Highly efficient and photothermally stable CDs@ZIF-8 for laser illumination

Carbon dots(CDs),as a solid-state phosphor,have great potential for application in a new solid-state lighting device—laser diode(LD).For high efficiency LD devices,both high photoluminescence quantum yield(PLQY)and high photothermal stability of CDs are essential.Herein,yellow CDs@ZIF-8 composites with high structural stability were prepared by encapsulating CDs in zeolitic imidazolate framework-8(ZIF-8)through electrostatic adsorption between CDs and ZIF-8,in which CDs with amino groups on the surface were used as luminescent feeders and ZIF-8 was used as a protective layer matrix.The asprepared CDs@ZIF-8 not only possess a high PLQY of up to 81.17%,but also maintain a high fluorescence intensity of 100%and 80%under long-term illumination(60 min)and high temperature(478 K),respectively.The hydrogen bonding between CDs and ZIF-8 in the encapsulated structure can enhance the degree of electron cloud delocalization,which can improve the PLQY of CDs@ZIF-8.Meanwhile,CDs@ZIF-8has high photothermal stability due to the binding effect of ZIF-8 on CDs and high thermal stability of ZIF-8.The white LD device,fabricated from CDs@ZIF-8 as a phosphor in combination with 450 nm blue LD,has a color coordinate of(0.37,0.33),a color temperature of 3762 K,and a high color rendering index of 86.This study provides a new strategy for the construction of solid-state phosphors with high PLQY and high photothermal performance.