溶剂对二维MoSe_2量子点发光性质的影响

Influence of solvents on luminescent properties of two-dimensional MoSe_2 quantum dots

采用液相超声剥离法一步制备了MoSe_2量子点,研究溶剂对MoSe_2量子点形貌和发光性质的影响。透射电子显微镜结果表明,所制备的MoSe_2量子点尺寸均匀、分散性良好,溶剂影响MoSe_2量子点的尺寸。所制备的MoSe_2量子点在可见光区和紫外光区各有1个发光峰,发光峰分别归属于MoSe_2量子点的缺陷态和本征态发光。能带带隙随量子点尺寸的减小而变大,导致发射峰蓝移;MoSe_2量子点表现出量子限制效应。对发光机制的认识将有助于设计量子点的尺寸与表面结构,获得新颖的发光特性。

MoSe_2 quantum dots(QDs)were prepared in various solvents by using ultrasonication-assisted liquid-phase exfoliation and the effects of solvents on the morphology and luminescent properties of MoSe_2 QDs were investigated.Transmission electron microscope results showed that the prepared MoSe_2 QDs have uniform size and good dispersibility,and the size of MoSe_2 QDs were determined by solvents.The prepared MoSe_2 quantum dots have one luminescence peak in the visible region and one in the ultraviolet region respectively,which were attributed to the surface defect and intrinsic luminescence of the MoSe_2 quantum dot.With the increase of the QD size,the bandgap increased and photoluminescence(PL)peak position blue-shifted.The MoSe_2 QDs exhibited quantum confinement effects.The understanding of the luminescent mechanisms would be helpful to design the size and surface structures of the QDs and achieve novel PL properties.