Properties of single-layer MoS2 film fabricated by combination of sputtering deposition and post deposition sulfurization annealing using (t-C4H9)2S2

The fabrication of a high-quality single-layer MoS2 film was achieved at a sufficiently low temperature of 500 °C by the combination of sputtering deposition and post deposition sulfurization annealing. Fabrication only by sputtering produces unintentionally sulfur-deficient nonstoichiometric films with poor crystalline quality in nature, making it difficult to fabricate atomically thin sputtered MoS2 films, especially with a single layer. From the results of the sulfurization annealing, sulfur deficiencies in the film were fully complemented and the crystalline quality, especially in-plane symmetry, was dramatically improved. The quasi-layered structure of the sputtered-MoS2 film led to the success in achieving low-temperature sulfurization annealing. Moreover, the film had large area uniformity, accurate thickness controllability, a direct bandgap of 1.86 eV, and an extremely high visible transmittance of more than 97%. Therefore, we consider that the fabrication technique will contribute to realizing MoS2 display applications such as a low-power-consumption thin-film-transistor liquid crystal display.