水相中长波长CdTe量子点的制备及其荧光性能

Synthesis and fluorescence spectrum analysis of long-wavelength CdTe quantum dots in aqueous solution

分别用谷胱甘肽(GSH)和巯基乙酸(TGA)为稳定剂,在水相中制备长波长荧光发射峰CdTe QDs。并用透射电子显微镜、X线粉末衍射和荧光光谱技术对其进行表征,研究不同水相合成条件对CdTe QDs荧光性能的影响。研究结果表明:以GHS为稳定剂制备得到的CdTe QDs为立方晶系纤锌矿结构,平均粒径约为5 nm,分散性良好。在2 h内能获得光发射峰为530～650 nm之间的任意波长量子点,具有明显的量子尺寸效应和较强的荧光强度;以TGA为稳定剂制备的CdTe QDs,平均粒径在10 nm以下,其中在水热条件下制备的CdTe QDs分散性较差,但能加快量子点的生长速率和荧光半峰宽的窄化。而在加热回流(分别为空气和氮气)条件下制备的CdTe QDs,分散性较好。相对于氮气保护氛围下的合成,通过氧气参与作用,也能加快CdTe QDs的生长。

CdTe QDs were synthesized in aqueous solution with two stabilizers（Glutathione（GSH） and thioglycollic acid（TGA）） by a simple route,respectively,and were characterized by transmission electron microscopy,X-ray diffractrometry,and fluorescence spectra.The effect of aqueous synthesis conditions on the fluorescence properties of CdTe QDs was investigated and the result shows that CdTe QDs by using GSH as a stabilizer was identified as cubicalnanocrystal with an even size of 5 nm.The CdTe QDs with the emission wavelength ranging from 530 nm to 650 nm could be synthesized in 2 h,and has obvious quantum size effect and strong fluorescence.However,hydrothermal method is applied into synthesis of CdTe QDs by using TGA,an even size of 10 nm of CdTe QDs is obtained with bad dispersivity,but higher temperature accelerates the growth rate and full width at half maximum（FWHM） narrowing of CdTe QDs,and oxygen plays an important role in the process of synthesis of CdTe QDs by refluxing and it can also accelerate the growth rate.