CdS量子点的一步法合成及量子产率

One-pot Synthesis of CdS Quantum Dots and Their Quantum Yields

以油酸为配体,十八烯为溶剂,采用一步法合成了CdS量子点,研究了反应温度、反应时间和Cd/S的摩尔比对量子点光谱性能的影响.X射线衍射(XRD)和高分辨透射电镜(HRTEM)测试结果表明,所获得的CdS量子点为立方闪锌矿结构,且尺寸分布均一,结晶度高,其较强的带边发光、尖锐的紫外吸收峰以及狭窄的荧光发射峰进一步表明量子点的单分散性及优异的光学性质.反应温度和Cd/S的摩尔比对CdS量子点的尺寸大小和荧光量子产率均有重要的影响.当n(Cd)/n(S)=3∶1及生长温度为240℃时,得到的CdS量子点单分散性良好且荧光量子产率高达30%.

CdS quantum dots（QDs） were synthesized via one-pot method,with Octadecene as the solvent and oleic acid as capping ligands.The influences of reaction time,reaction temperature and Cd/S molar ratio on optical properties of CdS QDs were studied.The zinc-blende,monodisperse and high-crystalline structures of CdS QDs were characterized by XRD and HRTEM.The good monodisperse size distribution and optical pro-perties were also confirmed by UV-Vis and PL spectra.The PL spectra are symmetrical and their full-width at half-maximum（FWHM） is samll.The first absorption peak is very sharp.The growth temperature and the initial Cd/S molar ratio have important influences on the size and photoluminescence quantum yields（PLQY） of CdS QDs.It has been demonstrated that high photoluminescence quantum yields with nearly monodisperse CdS nanocrystals can be obtained by a judicious choice of the Cd/S molar ratio（3∶1） and the growth temperature（240 ℃）,and the PLQY is about 30%.