Effect of Shell Thickness on the Optical Properties in CdSe/CdS/Zn0.5Cd0.5S/ZnS and CdSe/CdS/ZnxCd1鈥搙S/ZnS Core/Multishell Nanocrystals
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- 作者：Shasha Xu ; Huaibin Shen ; Changhua Zhou ; Hang Yuan ; Changsong Liu ; Hongzhe Wang ; Lan Ma ; Lin Song Li
- 刊名：Journal of Physical Chemistry C
- 出版年：2011
- 出版时间：November 3, 2011
- 年：2011
- 卷：115
- 期：43
- 页码：20876-20881
- 全文大小：867K
- 年卷期：v.115,no.43(November 3, 2011)
- ISSN：1932-7455
文摘
The evolution of optical properties of two types of core/multishell nanocrystals (NCs)鈥搕ype A (CdSe/CdS/Zn0.5Cd0.5S/ZnS) and type B (CdSe/CdS/ZnxCd1鈥?i>xS/ZnS)鈥攚ith an increase of shell thickness from 3.5 to 15.5 monolayers (MLs) has been studied. When the shell thickness was 9.5 MLs and more, the stability would be greatly improved and the quantum yields (QYs) almost did not change during the process of purification. Even after phase transfer experiment, the QYs of the water-soluble NCs were still kept 70鈥?9% of their initial level. The as-prepared water-soluble NCs with 9.5 MLs and more also exhibited high stability in varying physiological conditions under PBS buffer and continuous UV radiation. For type B core/multishell NCs, due to a consecutive change of lattice parameters from core to shells, there were almost no defects induced between the CdSe core and ZnS shell. As a result, they had higher QYs and stability than type A core/multishell NCs at the same test condition.