摘要
Here, a large-area monolayered WS2 thin film is synthesized via near atmospheric pressure chemical vapor deposition, and the effects of different parameter adjustments on the growth of the monolayered WS2 thin films are discussed. Unlike previous studies, which focused on the growth of WS2 flakes, the current study investigated the effect of two experimental configurations, face-up and face-down, on the growth of the WS2 from triangular flakes into large-area and high-coverage wafer-scale thin films. A series of Ar/H-2 gas ratio parameters for the monolayered WS2 growth and the effect of H-2 addition are discussed when the configuration is face-up. The following face-down method is the key strategy for the large-area growth of monolayered WS2 films. A large-area monolayered WS2 synthesis is successfully realized on half of a two-inch sapphire substrate by adjusting parameters such as temperature, pressure, carrier gas, and gas flow rate. Finally, a large-area monolayered WS2 film is used as the channel material to fabricate back-gate field-effect transistor arrays, with which I-on/I-off ratios of 10(5) to 10(6) and the highest carrier mobility of 0.84 cm(2)V(-1)S(-1) can be achieved.