Study of amorphous MoS2 films grown by pulsed laser deposition

The amorphous structure of MoS2 films prepared by pulsed laser deposition (PLD) has been evaluated with the use of Raman and X-ray photoelectron spectroscopy (XPS). The initial study of the room-temperature deposited films indicated a featureless Raman spectrum. On closer examination, however, four weak reproducible bands were observed. There has been some confusion in the literature as to the nature of this spectrum-whether it represents an amorphous MoS3 structure or a mixture of MoS2 and sulfur. Our interpretation of the Raman and XPS data indicates that the laser-deposited films represent a mixture of small domains of MoS2 and amorphous sulfur.