Facile Preparation of Four-Layer MoS₂ Nanosheets and Their Application to Organic Light-Emitting Diode

High-quality four-layer molybdenum disulfide (MoS₂) nanosheets with lateral dimension of about 11 µm were prepared by ultrasonic treatment of MoS₂ powder with assistance of 1-methyl-2-pyrrolidone (NMP) solvent. The optimal preparation conditions for the preparation of MoS₂ nanosheets were investigated from the aspects of ultrasonic processing time, ultrasonic power and amount ratio of MoS₂ powder and NMP solvent. At the same time, the MoS₂ nanosheets were employed as anode buffer layer in organic light-emitting diode (OLED) with copper nanowire (CuNW) film being anode. MoS₂ nanosheets can reduce roughness of CuNW film, protect CuNW film from oxidation and improve work function of CuNW film. Experiments show that MoS₂ nanosheets can significantly improve the current density and brightness of the OLED with CuNW film being anode. The maximum brightness of the OLED with MoS₂ anode buffer layer is 2.15 times that of the OLED without MoS₂ anode buffer layer. The current density of the OLED with MoS₂ anode buffer layer is also obviously increased compared with the OLED without MoS₂ anode buffer layer.