X-ray photoelectron spectroscopy of nickel dithiolene complex Langmuir-Blodgett films

The chemical states, composition, and structures of monolayer and multilayer Lagmuir-Blodgett (LB) films of a nickel dithiolene (BDN) complex and stearyl alcohol (SA), and BDN powder were characterized using X-ray photoelectron spectroscopy (XPS). The results indicate that Ni atoms mainly exist as Ni2+ in the LB films, while those exist in both Ni2+ and Ni-0 states in pure BDN powder. S-O and Ni-O bonds are more apparent in the XPS spectra of the LB films sample. The study of the peak features of S2p and Ni2p(3/2) with various thickness on silicon (with little silicon oxide surface) substrate indicates that chemisorption occurs in BDN molecules on a Si substrate. The electrical conductivity of BDN hulk and LB films and its relationship with the chemical state were also discussed. (C) 1999 Elsevier Science B.V. All rights reserved.