【摘要】 用巯基丙酸作稳定剂,在水溶液中制备了CdTe纳米晶.通过加入Cd2+、聚丙烯酸(PAA)以及长期放置分别得到了CdTe纳米晶的聚集体,改变Cd2+浓度或PAA加入量可以调控聚集体的尺寸.过量的Cd2+加速了聚集体的形成,通过与纳米晶表面羧酸根的静电相互作用,Cd2+成为连接不同CdTe纳米晶的“桥梁”.PAA链上大量的羧基与CdTe纳米晶有较强的配位相互作用,可以诱导纳米晶聚集.新制CdTe纳米晶在长期放置时,表面的羧基与Cd2+的相互作用导致纳米晶逐渐聚集.在聚集过程中纳米晶表面结构得到改善,并引起荧光增强.这些结果表明通过控制各种聚集条件,可以得到不同尺寸的聚集体.更多还原

【Abstract】 Water-soluble CdTe nanocrystals were prepared in the presence of 3-mercaptopropionic acid （MPA）.By adding additional Cd²⁺ or poly （acrylic-acid） （PAA） to the solution, aggregates of CdTe nanocrystals were obtained, and their size varied with the amount of Cd²⁺ or PAA.Cd²⁺ or PAA have an important effect on the aggregation process of CdTe.Additional Cd²⁺ can accelerate the formates of aggregates by linking with carboxyl on different CdTe particles,while PAA also acts as a linker between CdTe particles.When the freshly prepared nanocrystal solutions were stored for a long time,the interaction between the carboxyl and Cd²⁺ on different particles would lead to the formation of CdTe aggregation.The aggregation process was also a process of surface passivation which led to the dramatical increase of photoluminecence intensity.These results showed that the size of the aggregates could be controlled by adjusting various conditions of aggregation.更多还原