Facile Preparation of Four-Layer MoS(2) Nanosheets and Their Application to Organic Light-Emitting Diode

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