化学学报 ›› 2007, Vol. 65 ›› Issue (21): 2479-2483. 上一篇    下一篇

研究论文

温度对聚酰胺-胺树形分子模板法制备CdS量子点的影响

丛日敏,罗运军*,靳玉娟   

  1. (北京理工大学材料科学与工程学院 北京 100081)
  • 投稿日期:2006-06-30 修回日期:2007-01-10 发布日期:2007-11-14
  • 通讯作者: 罗运军

Effect of Temperature on the Preparation of CdS Quantum Dots Us-ing Poly(amide amine) Dendrimer Templates

CONG Ri-Min; LUO Yun-Jun*; JIN Yu-Juan   

  1. (School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081)
  • Received:2006-06-30 Revised:2007-01-10 Published:2007-11-14
  • Contact: LUO Yun-Jun

为了研究温度对聚酰胺-胺(PAMAM)树形分子的模板法制备硫化镉(CdS)量子点的影响, 以4.5代(G4.5, 64个甲酯端基)PAMAM树形分子为模板, 在-10~30 ℃的温度范围内制备了分散良好的CdS量子点. 用透射电子显微镜(TEM)表征了CdS量子点的形貌、尺寸; 用紫外-可见光谱(UV-Vis)和光致发光光谱(PL)表征了CdS量子点的光学性能. 发现在相同条件下, 制备温度从-10 ℃升高到30 ℃, CdS量子点粒径从1.8 nm增大到3.4 nm, 其中在10 ℃时制备的量子点的尺寸分布最窄; CdS量子点的吸收和发射光谱均随温度增大而红移, 其中10 ℃时制备的量子点的室温光致发光效率最高. 这表明制备温度决定了树形分子的配位基团与Cd2+的分离速度, 并影响了CdS量子点的成核和生长过程, 从而最终决定了CdS量子点的尺寸及尺寸分布、光致发光颜色和发光效率.

关键词: CdS量子点, PAMAM树形分子, 制备温度, 光致发光

In order to study the effect of temperature on the preparation of CdS quantum dots (QDs) using poly(amide amine) (PAMAM) dendrimer templates, well-dispersed CdS QDs were synthesized with PAMAM dendrimers of generation 4.5 (G4.5, 64 terminal ester groups) in the temperature range from -10 to 30 ℃. The morphology and the size of CdS QDs were measured using TEM. The optical properties were charac-terized by UV-Vis spectra and photoluminescence (PL) spectra. The results show that the size of CdS QDs increased from 1.8 to 3.4 nm when the synthesis temperature was raised from -10 to 30 ℃, and the size-distribution of QDs prepared at 10 ℃ was the narrowest; the absorption and the PL spectra were red-shifted, while the PL intensity of CdS QDs prepared at 10 ℃ was the highest. These results suggest that the preparation temperature determines the de-coordination rate between the functional groups of PAMAM dendrimers and Cd2+, the rate of nucleation and growth of CdS QDs , the size and size-distribution of QDs, and the PL color and PL efficiency finally.

Key words: CdS quantum dot, PAMAM dendrimer, preparation temperature, photoluminescence