Wurtzite GaN films were synthesised on p-Si(1 0 0) and n-Si(1 0 0) substrates by plasma assisted hot wall vapour deposition technique without using any buffer layer. The films were characterised by electrical and optical measurements while the microstructural. information was obtained from atomic force microscopy (AFM) and X-ray diffraction (XRD) studies. The compositional study for the GaN film was carried out using SIMS. Photoluminescence (PL) measurement at room temperature exhibited near band edge (BE) emission at similar to363 nm (3.4 eV) along with a broad yellow band. The bonding environment in the film was revealed from FTIR studies. Schottky diode (Au/GaN), fabricated with hexagonal GaN film on n-Si substrate, was characterised by I-V and C-V analysis. (C) 2002 Elsevier Science B.V. All rights reserved.