Optical and electrical properties of Al:WS2 films prepared by atomic layer deposition and vulcanization

Composition, structure, optical and electrical properties of Al:WS2 (un-doped and Al-doped WS2) films prepared by atomic layer deposition (ALD) and CS2 vulcanization processing have been studied. Results show that Al:WS2 films grow with a preferential c(perpendicular to)-orientation. The core-level binding energies (BEs) of W 4f, S 2p, O 1s and Al 2s decrease with increasing Al doping content, indicating that Al-doped WS2 films have a p-type conductivity. Optical property analysis shows that the absorption coefficient (similar to 10(7) m(-1)) is comparable to that of WS2 single crystals and that Al doping content can tune the optical band gap of the films. Hall measurements show that p-type conductive Al-doped WS2 films can be obtained by Al doping. Hall mobility values for the un-doped WS2 and 2.40% Al-doped WS2 films are 1.63 x 101 and 9.71 cm(2) V (1) s (1), respectively. Comparing with un-doped WS2 films, the comparable Hall mobility of Al-doped WS2 films can be achieved by appropriate Al doping contents.