Influence of precursor thin-film quality on the structural properties of large-area MoS2 films grown by sulfurization of MoO3 on c-sapphire

In recent years, molybdenum disulfide (MoS2) has been investigated due to its unique electronic, optical, and mechanical properties with a variety of applications. Sulfurization of pre-deposited MoO3 layers is one of the methods of the preparation of large-area MoS2 thin films. The MoO3 layers have been grown on c-sapphire substrates, using two different techniques (rf sputtering, pulsed laser deposition). The films were subsequently annealed in vapors of sulfur at high temperatures what converted them to MoS2 films. The quality of MoS2 is strongly influenced by the properties of the precursor MoO3 layers. The pre-deposited MoO3, as well as the sulfurized MoS2, have been characterized by several techniques including Raman, Rutherford backscattering spectroscopy, atomic force microscopy, scanning electron microscopy, and X-ray diffraction. Here we compare two types of MoS2 films prepared from different MoO3 layers to determine the most suitable MoO3 layer properties providing good quality MoS2 films for future applications.