摘要
以巯基乙酸为稳定剂,在水相中制备了CdSe纳米晶水溶胶,并用X射线光电子能谱和透射电子显微镜对其进行了表征,证明了CdSe纳米晶的形成。研究了在不同反应时间所制备的CdSe纳米晶的XRD谱以及吸收光谱和发射光谱的变化情况,并且还研究了不同反应物配比情况下的发射光谱的变化,结果表明改变CdSe纳米晶的制备条件,将会对CdSe纳米晶的发光特性有显著的影响。
Water-colloid cadmium selenide semiconductor nanocrystals were prepared in aqueous solution by using mercaptoacetic acid as stabilizer. The samples were characterized by X-ray photoelectron spectroscopy （XPS） and transmission electron microscopy（TEM）. The results of XPS confirmed the formation of CdSe nanocrystals, and the images of TEM demonstrated that the average size of CdSe nanocrystals was less than 10 nm and the aggregation occurred among the nanocrystals. The changes of the XRD patterns, absorption spectra and emission spectra of the CdSe nanocrystals prepared for different time were investigated. The XRD patterns showed that the crystal structure became more perfect with the increasing preparation time. It was found that the emission peak changed from 550 nm to 572 nm, but no distinct changes for the shape and full width at the half maximum of the spectra were observed, but the absorption peak changed from 443 nm to 483 nm. The extent of the peak changes became less and less with the reaction time, which was attributed to the growth of the CdSe nanocrystals with the reaction time at the initial moment and the control of the growth due to the stabilizer mereaptoacetic acid at the ultimate moment. The emission spectra for the different molar ratios of the reactant were also investigated, and the results indicated that the wavelength of the emission peak shifted to the longer wavelength as the molar ratio of Se^2-/Cd^2＋ increased, and it could be interpreted as followings： In the competition between the reaction of Cd^2＋ with HSe^- and RS^- , the reaction between Cd^2＋ and HSe^- occupied the predominance with the increasing of Se amount, which made the size of the nanocrystals increase. All the results indicated that the varying of the preparation conditions would influence on the luminescence properties greatly.
出处
《发光学报》
EI
CAS
CSCD
北大核心
2005年第5期622-626,共5页
Chinese Journal of Luminescence
基金
国家重点基础研究发展计划(2003CB314707)
国家自然科学基金(90301004
10434030
60406005)
北京市科技新星计划(2004B10)资助项目
关键词
CDSE纳米晶
制备条件
发光特性
CdSe nanocrystals
preparation conditions
luminescence properties
