Pulsed Laser Deposition of Large-Area Molybdenum Disulfide Thin Films for THz Applications

Thin MoS films with a thickness of three to 30 monolayers of a large area on c-AlO substrates were obtained by the pulsed laser deposition. The MoS films were synthesized using MoS targets manufactured according to the developed technique at a substrate temperature of 700 and 770°C. The influence of laser synthesis conditions and substrate temperature on the deposition rate, optical and electrical characteristics of the MoS films was studied. The film thickness was controlled by the number of laser pulses, which was confirmed by the atomic force microscopy and Raman spectroscopy. A clear dependence of the characteristic phonon modes of Raman scattering on the number of monolayers was observed in the spectra of MoS films. With an increase in the number of monolayers in the film, the position of the photonic modes E and A were found to shift to the red and blue regions of spectrum, respectively, and the distance between them changed from 25 to 26.9 cm for the number of pulses increasing from 24 to 720, respectively, at a growth temperature of 770°C.