Growth dynamics of pulsed laser deposited WS2 thin films on different substrates

The scaling behavior, as well as growth mechanism of polycrystalline WS 2 thin films grown on glass and Si substrates by pulsed laser deposition as a function of the deposition time, has been studied using height–height correlation function using the AFM images. X-ray diffraction measurement confirms the increase in crystallinity of the WS 2 thin film on both the substrates. The WS 2 films deposited onto Si substrate showed high rate of roughening or interface width ( w ) and a rapid increase in island size or correlation length ( ξ ) of WS 2 nanoclusters in comparison to the films deposited onto glass substrate. The WS 2 films grown on glass substrate evolved following the nonlinear stochastic deposition equation, however, WS 2 films on Si substrate follow a linear growth model. The difference in surface smoothness, thermal conductivity and sticking coefficient of the two substrates causes different growth patterns of WS 2 films onto the substrates. The growth of the WS 2 films on the two different substrates evolved differently which has been realized more conveniently by schematically analyzing the behavior of the evolution of ξ and w with deposition time, t . The high roughness of the films deposited onto oxidized Si provides a large surface area, which will be useful for electro-catalysis applications.