Study On The Structure And Properties Of MoS₂ Films Prepared By Magnetron Sputtering

Molybdenum disulfide（MoS₂）films were prepared by RF magnetron sputtering technology under different deposition conditions.The structure,composition,and properties of the MoS₂ films were controlled by controlling the sputtering deposition conditions.Scanning electron microscope（SEM）,atomic force microscope（AFM）,X-ray diffractometer（XRD）,Raman spectrometer（Raman）,and X-ray photoelectron spectroscopy（XPS）were used to investigate the surface morphology,structure,and composition of the films.The friction material tester and performance of the films were tested by the UV-Vis spectrometer（UV-Vis）,fluorescence spectrometer（PL）,and Hall effect tester.This works focused on the effects of sputtering power,deposition pressure,and annealing temperature on the composition,structure,and micro-morphology of MoS₂ films,and explores the intrinsic relationship between the film preparation process parameters,micro-structures,and properties.The results show as follows:1.The effects of sputtering power on the structure and friction properties of MoS₂films were studied.The results show that as the power increases,the crystallinity of the film gradually increases.The grain size increases and then decreases slightly,and the friction coefficient decreases and then increases.The film deposited at 300 W possessed a dense and smooth surface,uniform grain distribution,and a relatively low friction coefficient（about 0.0863）.This is mainly due to the small initial friction coefficient of the smooth surfaces.When large-sized particles fall off the film surface,a sliding friction is provided,thereby making the friction coefficient small.2.The effects of deposition pressure on the structure and optical properties of MoS₂ films were studied.The results show that the crystallinity and optical band gap of the film both increase with the increasing pressure,and then decrease.The optical band gap of the films prepared by magnetron sputtering range from 1.58 to 1.64 eV.The crystallinity of 1.0 Pa deposited film is the highest among the prepared samples,with an average grain size of 30.35 nm and an optical band gap of 1.67 e V.At the same time,it was found that the trace MoO₃ impurities and the large electronegativity in MoS₂ molecules make the film prone to defects.The exciton energy near these defects is low and the surrounding energy band is modulated.3.A large-area MoS₂ films were prepared and annealed at high temperature.The effect of annealing temperature on the electrical properties of the films were studied.Researches have shown that as the annealing temperature increases,the crystallinity of the MoS₂ films gradually increases,and the Fermi level moves to the valence band.When the annealing temperature exceeds 900℃,the Hall mobility and carrier concentration of the film are 4.40 cm²/Vs and 125.06×10²⁰ cm^-2,respectively,and the conductivity type is changed from n-type to p-type.The analysis found that the anisotropy of the electrical transmission of the MoS₂ film caused its Hall coefficient to switch between negative and positive values at high temperatures;the increase in crystallinity enhances the contact at the grain boundaries and affects the transport of free electrons;high temperature annealing causes more S vacancies to appear,making hole transport the main conductive carrier of the films.