为了明确溶剂对MoS2量子点发光的影响, 以液相剥离法在N-甲基吡咯烷酮(NMP)与1,2-二氯苯(DCB)的混合溶剂中制备了MoS2量子点, 并采用透析的方法对照研究了溶剂及含有MoS2量子点的溶液的发光性质。结果表明, 量子点尺寸分布均匀, 粒径约2.4 nm。拉曼光谱中可在381 cm-1和406 cm-1处观察到MoS2材料的E12g和A1g拉曼特征峰。光学性质分析表明, MoS2量子点的存在造成了260～400 nm附近紫外光吸收的明显变化, 且混合溶剂中的MoS2量子点荧光发射波长对激发波长表现出严重的依赖性。以水为外部环境的透析实验结果表明, 透析后DCB溶剂的HOMO能级会导致MoS2量子点在442 nm附近的发光出现多个发射峰, 但其发光波长不再随激发波长而改变, 进而说明有机溶剂中MoS2量子点发光对激发波长的依赖性是由于有机溶剂在紫外光激发下发光造成的。

In order to elucidate the effect of solvent on the luminescence of MoS2 quantum dots, MoS2 quantum dots were prepared by liquid phase stripping method in a mixed solvent of N-Methyl pyrrolidone(NMP) and 1,2-dichlorobenzene(DCB). The dialysis method was utilized to compare the luminescent properties of the solvent and the solution containing the MoS2 quantum dots. The results show that the quantum dot size distribution is uniform and the particle size is about 2.4 nm. The E12g and A1g Raman characteristic peaks of the MoS2 material were observed at 381 cm-1 and 406 cm-1 in the Raman spectrum. It was found that the presence of MoS2 quantum dots caused a significant change in the absorbance spectra around 260-400 nm, and the emission wavelength of MoS2 quantum dots in the mixed solvent seriously depended on the excitation wavelength. The results of dialysis experiments with water as the external environment show that the HOMO level of DCB solvent will cause multiple emission peaks in the luminescence of MoS2 quantum dots near 442 nm, but the emission wavelength will no longer change with the excitation wavelength, indicating the dependence of the luminescence of MoS2 quantum dots on the excitation wavelength is due to the luminescence of the organic solvent under ultraviolet excitation.