水相中CdTe纳米晶的制备及其光学性质

摘要

用不同稳定剂(巯基乙酸(TGA)、巯基丙酸(MPA)、L-半胱氨酸(L-Cys)、3-巯基-1,2-丙二醇(TG))在水相中制备了CdTe纳米晶,并用透射电子显微镜(TEM)、X射线光电子能谱(xPS)和X射线粉末衍射(XRD)等技术对其进行了表征.研究了不同水相合成条件对CdTe纳米晶光学性质的影响,结果表明,n(Cd):n(Te)、溶液pH值、回流时间以及稳定剂的性质,对纳米晶的光学性质具有显著影响.制得的CdTe纳米晶发射峰窄且对称(半高全宽达38 nm),用不同稳定剂制备的纳米晶发光量子效率有所不同,用不同的激发波长对纳米晶进行激发时,发射峰并未表现出明显的移动.%CdTe nanocrystals were synthesized in aqueous solution with different stabilizers (L-cysteine hydrochloride (L-Cys), 3-mercaptopropionic acid (MPA), 1-thioglycerol (TG), and thioglycolic acid (TGA)) by a simple route, and were characterized by transmission electron microscopy (TEM), X-ray photoelectron spectra (XPS), and X-ray diffraction pattern (XRD). The effect of aqueous synthesis conditions on the optical properties of CdTe nanocrystals was investigated and it was found that the molar ratio of Cd/Te, pH value, refluxing time, and different stabilizers significantly affected the optical properties of CdTe nanocrystals. The obtained CdTe nanocrystals exhibited a favorable narrow emission band under different conditions. The photoluminescence (PL) peaks and absorption peaks could be tuned by changing the synthesis conditions of CdTe nanocrystals. Different PL quantum yields (QY) were obtained using different stabilizers. The PL peak position of CdTe nanocrystals did not show significant shift under different excitation wavelengths.