物理化学学报 >> 2014, Vol. 30 >> Issue (5): 994-1000.doi: 10.3866/PKU.WHXB201403131

材料物理化学 上一篇    

基于聚合物多齿配体的高性能CdTe量子点的微波水相合成

宇文力辉, 薛冰, 汪联辉   

  1. 南京邮电大学信息材料与纳米技术研究院, 南京210023
  • 收稿日期:2013-12-20 修回日期:2014-03-12 发布日期:2014-04-25
  • 通讯作者: 汪联辉 E-mail:iamlhwang@njupt.edu.cn
  • 基金资助:

    国家重大科学研究计划(2012CB933301),国家自然科学基金(21204038,81273409),教育部长江学者和创新团队发展计划(IRT1148),教育部博士点基金(20123223110007),江苏省自然科学基金(BK20130862),江苏省高校自然科学基金(13KJB150029),东南大学生物电子学国家重点实验室和南京大学配位化学重点实验室开放研究基金资助

Synthesis of High Quality CdTe Quantum Dots in Aqueous Solution Using Multidentate Polymer Ligands under Microwave Irradiation

YUWEN Li-Hui, XUE Bing, WANG Lian-Hui   

  1. Institute of Advanced Materials, Nanjing University of Posts and Telecommunications, Nanjing 210023, P. R. China
  • Received:2013-12-20 Revised:2014-03-12 Published:2014-04-25
  • Contact: WANG Lian-Hui E-mail:iamlhwang@njupt.edu.cn
  • Supported by:

    The project was supported by the Major Research Plan of China (2012CB933301), National Natural Science Foundation of China (21204038, 81273409), PCSIRT of the Ministry of Education of China (IRT1148), Ph.D. Programs Foundation of Ministry of Education of China (20123223110007), Natural Science Foundation of Jiangsu Province, China (BK20130862), Natural Science Foundation of Universities from Jiangsu Province, China (13KJB150029), Open Research Fund of State Key Laboratory of Bioelectronics, Southeast University, China and Open Research Fund of State Key Laboratory of Coordination Chemistry, Nanjing University, China.

摘要:

针对当前水相合成的量子点(QDs)光性能与稳定性等方面存在的不足,发展了基于聚合物多齿配体的水相制备策略. 利用巯基修饰的聚丙烯酸(PAA-SH)作为多齿配体代替常用的巯基丙酸等单齿配体,结合微波辅助加热制备了CdTe 量子点,研究了多齿配体对量子点的生长机制与荧光性能的影响. 以PAA-SH为配体制备的CdTe量子点荧光性能优异(荧光量子效率(PLQY)可达75%),流体力学直径较小(~10 nm),稳定性也有明显提高. 基于聚合物多齿配体的量子点制备技术有助于实现生物医学研究中急需的兼具高亮度、高稳定性、小尺寸等特征的高性能量子点生物探针的制备.

关键词: 多齿配体, 高性能, 量子点, 微波水相合成

Abstract:

Quantum dots (QDs) have recently attracted considerable attention due to their unique optical properties and potential applications in biomedicine and optoelectronics. Although the organic synthesis of QDs is popular, aqueous synthesis is also very attractive not only for its low cost, low toxicity, and low reaction temperature, but also because the as-prepared QDs can be used directly for bio-related applications without the requirement for complicated surface modification processes. However, the monodentate ligands typically used for aqueous synthesis have limited binding ability, which can lead to weak colloidal stability and low photoluminescence. To solve these problems, we explored the use of multidentate thiol-containing polymer (PAASH) as a ligand to synthesize CdTe QDs and studied the influence of the ligand on the growth mechanism and photoluminescent properties of the QDs. PAA-SH was synthesized by conjugating cysteamine to poly(acrylic acid) (PAA) in the presence of dicyclohexylcarbodiimide. CdTe QDs of different sizes were prepared in aqueous solutions using PAA-SH as a ligand under microwave irradiation. The resulting PAA-SH-capped CdTe QDs show high photoluminescence quantum yield (PLQY) (up to 75%) without CdS shell coating, which is much better than the CdTe QDs synthesized using monodentate ligands. Furthermore, the hydrodynamic diameter of the PAA-SH-coated CdTe QDs is about 10 nm, and therefore much smaller than the polymer or SiO2 encapsulated QDs. In contrast, benefitting from cooperative binding effect of the multiple thiol groups and the high free energy for the ligand detachment from the QDs surface, PAA-SH-CdTe QDs show high storage stability.

Key words: Multidentate ligand, High quality, Quantum dots, Microwave aqueous synthesis

MSC2000: 

  • O649