Atomically thin molybdenum disulfide (MoS2) films were synthesized on a SiO2/Si substrate by metal-organic chemical vapor deposition (MOCVD). Raman spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy studies reveal the double-atomic-layer
structure and the surface element composition of the MOCVD-grown MoS2 films. The photoluminescence measurement demonstrates a strong emission peak with a bandgap of 685.1 nm, attributed to highly efficient radiative transition at the double atomic layer. The contact resistance between
the doubleatomic-layer MoS2 film and metal electrode was measured using the transmission-line modeling method. A Ti/Au electrode forms an ohmic contact with the double-atomic-layer MOCVD-grown MoS2 film, exhibiting a resistivity of 100 kΩ. The field-effect transistor
based on the double-atomiclayer MoS2 film exhibits an electron mobility of 1.3×10−4 cm2/V·s and an on/off ratio of 6.5×102 at room temperature.