CdSe∶X/ZnS掺杂型核壳量子点的化学合成及光谱性质研究

Chemical synthesis and spectroscopic properties of doped CdSe∶X/ZnS core-shell quantum dots

采用绿色合成工艺,通过在核壳量子点中掺杂不同的金属离子,在水溶液中合成了CdSe∶X/ZnS掺杂型核壳量子点。并利用多种分析测试手段对合成产物的结构以及光谱性质进行了详细地研究。XRD分析表明,核壳结构的量子点的衍射峰相对内层CdSe量子点向高角度方向移动,掺杂型核壳量子点的衍射峰较未掺杂量子点有向高角度移动趋势,合成量子点的平均晶粒尺寸约为2.3nm。SEM结果表明,合成的核壳量子点近似为球形。量子点的吸收峰与体材料相比,产生明显的蓝移,表现出明显的量子限域效应。样品具有很好的亲水性,在红外光线照射下出现丁达尔效应,样品的FT-IR结果表明配体MPA成功包覆在量子点的表面。

CdSe∶X/ZnS doped core-shell quantum dots were successfully synthesized in aqueous solution by a green synthetic route. The structural and spectroscopic properties of the synthesized products were studied in detail via using a variety of analytical methods. XRD results show that the diffraction peaks of core-shell quantum dots shifted to high angle direction relative inner CdSe quantum dots, and the diffraction peaks of doped core-shell quantum dots also moved to high angle region with respect to undoped quantum dots. The obtained quantum dots had the average grain size of about 2.3 nm. SEM results display that the shape of the produced quantum dots was nearly spherical. Compared with the corresponding bulk materials, the absorption peaks of the quantum dots displayed a significant blue shift, which revealed the obvious quantum confinement effect. The synthesized samples had good hydrophilicity, and Tyndall effect appeared under the infrared light irradiation. The FT-IR results exhibit that ligand MPA successfully was coated on the surface of quantum dots.