 The abstract states that two-dimensional transition metal dicalcogenide, TMD, monolayers have been pursued extensively in recent years for their interesting physics and application potentials. It is important to synthesize crystalline TMD monolayers at wafer scale for applications. In this study, molecular beam epitaxy was used to grow single crystal monolayers of molybdenum disulfide, MOS2, or tungsten disulfide, WS2, at low temperatures, 200 to 400 degrees Celsius, on nominally flat gold, 111 substrates. The epa films had low intrinsic defect densities of less than 10 superscript 1 superscript 2Cm-2. The grown films were then exfoliated and transferred onto silicon dioxide slash silicon using a wet chemical process. Optical measurements revealed high spatial uniformity of the samples. The authors identified that the growth of highly crystalline MOS2 or WS2 is promoted by an increased interaction between the gold substrate and the TMD island rather than by the guidance of surface steps on the substrate. This interaction only stops lateral growth when this article was authored by Pusia, Degongding, Kushao, and others. We are article.tv, links in the description below.