CdSe:Zn/ZnS核壳量子点的化学合成及光谱性质研究

Chemical synthesis and spectroscopic properties of CdSe:Zn/ZnS core-shell quantumdots

摘要:

采用绿色合成工艺，使用多种配体分别在水溶液中合成了水溶性的CdSe:Zn/ZnS核壳量子点，并通过多种测试手段对产物的结构及光谱性质进行讨论。XRD结果表明，合成的CdSe:Zn/ZnS核壳量子点为立方闪锌矿结构，产物的平均晶粒尺寸约为2.4 nm，相比未加配体得到的量子点的晶粒要小一些。SEM图像表明合成的样品为近球形颗粒。有趣的是，合成的样品具有良好的的亲水性，推断样品的表面包覆有亲水性基团，该推断与FT-IR结果相吻合。量子点的吸收峰位与相应的体材料相比，均产生明显的蓝移，展示出明显的量子限域效应。

Abstract:

Water–soluble CdSe:Zn/ZnS core-shell quantum dots were successfully synthesized in aqueous solution by a green synthetic route using a variety of ligands, and the effects of ligands on the structure and optical properties of the quantum dots were explored through a variety of analytical methods. XRD results show that the obtained CdSe:Zn/ZnS core-shell quantum dots possess cubic sphalerite structure of ZnS phase and their average grain size is about 2.4 nm, which is smaller compared with that of sample fabricated without ligands. SEM result shows that the shape of CdSe:Zn/ZnS is nearly spherical. Interestingly, the synthesized samples have good hydrophilicity, and the surfaces of the samples are coated with hydrophilic groups, which is consistent with the FT-IR results. Compared with the corresponding bulk materials, the absorption peaks of the quantum dots display a significant blue shift, demonstrating the obvious quantum confinement effect.