Jung Hyunchul, Chung Wonkeun, Lee Chang Hun, Kim Sung Hyun
Department of Chemical and Biological Engineering, Korea University, 1 Anam-Dong, Sungbuk-Gu, Seoul 136-701, South Korea.
J Nanosci Nanotechnol. 2012 Jul;12(7):5407-11. doi: 10.1166/jnn.2012.6288.
White light-emitting diodes (LEDs) were fabricated using GaN-based 380-nm UV LEDs precoated with the composite of blue-emitting polymer (poly[(9,9-dihexylfluorenyl-2,7-diyl)-alt-co-(2-methoxy-5-{2-ethylhexyloxy)-1 ,4-phenylene)]), yellow green-emitting polymer (poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(1,4-benzo-{2,1',3}-thiadiazole)]), and 605-nm red-emitting quantum dots (QDs). CdSe cores were obtained by solvothermal route using CdO, Se precursors and ZnS shells were synthesized by using diethylzinc, and hexamethyldisilathiane precursors. The optical properties of CdSe/ZnS QDs were characterized by UV-visible and photoluminescence (PL) spectra. The structural data and composition of the QDs were transmission electron microscopy (TEM), and EDX technique. The quantum yield and size of the QDs were 58.7% and about 6.7 nm, respectively. Three-band white light was generated by hybridizing blue (430 nm), green (535 nm), and red (605 nm) emission. The color-rendering index (CRI) of the device was extremely improved by introducing the QDs. The CIE-1931 chromaticity coordinate, color temperature, and CRI of a white LED at 20 mA were (0.379, 0.368), 3969 K, and 90, respectively.
白色发光二极管（LED）是通过使用基于GaN的380纳米紫外LED制造的，该紫外LED预先涂覆有蓝色发光聚合物（聚[(9,9-二己基芴基-2,7-二基)-alt-共-(2-甲氧基-5-{2-乙基己氧基)-1,4-亚苯基}])、黄绿色发光聚合物（聚[(9,9-二辛基芴基-2,7-二基)-共-(1,4-苯并-{2,1',3}-噻二唑)]）和605纳米红色发光量子点（QD）的复合材料。CdSe核通过使用CdO、Se前驱体的溶剂热法获得，ZnS壳层通过使用二乙基锌和六甲基二硅硫烷前驱体合成。CdSe/ZnS量子点的光学性质通过紫外可见光谱和光致发光（PL）光谱进行表征。量子点的结构数据和组成通过透射电子显微镜（TEM）和能谱仪（EDX）技术确定。量子点的量子产率和尺寸分别为58.7%和约6.7纳米。通过混合蓝色（430纳米）、绿色（535纳米）和红色（605纳米）发射产生三波段白光。通过引入量子点，器件的显色指数（CRI）得到了极大提高。在20毫安时，白色LED的CIE-1931色度坐标、色温及CRI分别为(0.379, 0.368)、3969 K和90。
