Aerosol-assisted chemical vapor deposition of 2H-WS2 from single-source tungsten dithiolene precursors

The tungsten carbonyl dimethyldithiolene (dmdt) complexes W(CO)(4)(dmdt), W(CO)(2)(dmdt)(2), and W(dmdt)(3) were evaluated as potential single-source precursors for the chemical vapor deposition of WS2. The results of TGA-MS, DIP-MS, and pyrolysis with NMR analysis were consistent with a thermal decomposition pathway in which loss of 2-butyne through a retro[3+2]cycloaddition of the dithiolene ligand generated terminal sulfido ligands. Aerosol-assisted chemical vapor deposition onto silicon substrates was performed using all three complexes, yielding 2H-WS2 thin films as characterized by Raman spectroscopy and GI-XRD. Film morphology and elemental composition of the films were determined using SEM, EDS, and XPS. Four-point probe measurements afforded a film resistivity of 8.37 Omega cm for a sample deposited from W(dmdt)3 in toluene at 600 C-degrees.