CdSe/CdS核壳量子点复合材料合成及其在白光发光二极管中的应用

采用有机化学合成法,利用正三辛基膦(TOP)辅助的快速注入生长方法,改进传统的制备工艺,实现了CdSe/CdS厚壳层核壳(8.6 ML)量子点复合材料的合成制备,并对所合成的核、核壳量子点及其复合材料的晶格结构、形貌特点与发光性质进行了XRD、TEM、SEM、UV-Vis、PL表征和红光补偿效果测试。测试结果表明,CdSe核具有立方纤锌矿晶格结构;CdSe/CdS量子点复合材料直径为45~75μm,呈菱形规则形貌,且颗粒分散性良好。采用该方法,可以提高量子产率,产率由4%(CdSe核)升至48%(CdSe/CdS核壳量子点);可以增强激子态发光能力,CdSe/CdS核壳量子点复合材料的荧光强度约为CdSe核的13倍。将该材料与YAG∶Ce~(3+)黄色荧光粉组合应用,获得了高光效(148.29 lm/W)、高显色指数(Ra为90.1,R9为97.0)的白光发光二级管,表明按照上述方法获得的CdSe/CdS核壳量子点复合材料在白光发光二极管中深红光波段具有较好的补偿效果。

Synthesis of CdSe/CdS Core/Shell Quantum Dots Luminescent Microspheres and Their Application for WLEDs

By adopting three trioctylphosphine (TOP) assisted rapid injection growth method,and combining a composite material for fluorescent quantum dot micro-nano packaging, CdSe/CdS core-shell quantum dots luminescent microspheres (LMS) with thick shell(8.6 ML)were synthesized.It is an organic-synthesis method.The lattice structure, morphology composition and optical properties of the as-prepared, core-shell quantum dots and LMS were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV-Vis absorption, photo-luminescence spectrum (PL) and red-light compensation test, respectively.The obtained CdSe core has a cubic phase zinc blend structure.The diameters of LMS are about 45-75 μm with diamond rules of morphology, and the particles disperse in order.The method aforementioned can improve the quantum yield.The quantum yield is improved from 4% (CdSe core) to 48% (CdSe/CdS core-shell quantum-dots).Besides, the luminous power of exciton-states is enhanced, and the fluorescence intensity of CdSe/CdS core-shell quantum-dots is about 13 times larger than that of CdSe core.By applying the LMS and YAG∶Ce3+ yellow phosphor combination, the white light-emitting diode (WLED) with high efficiency (148.29 lm/W) and high color rendering index (Ra is 90.1, R9 is 97.0) are obtained.The results indicate that the LMS have good compensation effect for the deep-red-light-band.