树形分子包覆硫化镉量子点的抗老化性能研究  

Study on the Resistance to Aging of CdS Quantum Dots Encapsulated by PAMAM Dendrimers

作　　者：丛日敏[1] 罗运军[2] 于怀清[1] 

机构地区：[1]山东理工大学材料科学与工程学院,淄博255049 [2]北京理工大学材料科学与工程学院,北京100081

出　　处：《无机材料学报》2008年第2期379-382,共4页Journal of Inorganic Materials

基　　金：北京理工大学基础研究基金(BIT-UBF-200504E4203);山东理工大学科技博士基金(4041-406038)

摘　　要：以聚酰胺-胺树形分子为模板制备了平均粒径为2.5nm的CdS量子点,采用HRTEM、EDS、UV-vis、PL等手段对样品进行表征,研究了其在室温避光条件下的老化过程.结果表明,CdS量子点在刚制备的前5d里UV-vis、PL谱峰半峰宽变窄,发光效率迅速上升,表明量子点以尺寸窄化生长为主;5d后UV-vis、PL谱峰半峰宽逐渐宽化,发光效率缓慢下降,表明量子点以尺寸宽化(Ostwald熟化)过程为主.树形分子的配位作用和模板作用赋予CdS量子点良好的抗老化性能,6个月后量子点粒径增量<0.3nm,PL强度约降低22%.CdS quantum dots （QDs） of 2.5nm were prepared using G4.5 PAMAM dendrimer templates and characterized by HRTEM and EDS. The aging of synthesized QDs stored in the dark at roomtemperature was studied through UV-vis and PL spectrophotometer. The width at half-maximum of the peak （WHM） of the UV-vis and PL spectra becomes narrower, meanwhile the PL intensity increases obviously during the first 5d. Afterwards, the WHM gets broader and the PL intensity decreases slowly during the following 6 months. The results suggest that CdS QDs show a size-focusing growth within the first 5d, but a size-defocusing growth in the following 6 months. However, the increment of CdS QDs size is less than 0.3nm, and the decrement of PL intensity is about 22% after 6 months of aging. The excellent resistance to aging of CdS QDs is attributed to the coordination and template effects of PAMAM dendrimers.

关 键 词：CDS量子点 PAMAM树形分子 光致发光 老化 

分 类 号：O614[理学—无机化学]