Atmospheric pressure chemical vapour deposition of TiS 2 thin films on glass

Abstract

Atmospheric pressure chemical vapour deposition (APCVD) of TiS 2 films on glass substrates was achieved by reaction of HS(CH 2) 2SH, HSC(CH 3) 3 and S(Si(CH 3) 3) 2 with TiCl 4 at 275–600 °C. At substrate temperatures from 275 to 400 °C, the TiS 2 films were X-ray amorphous or nanocrystalline. At 500 °C and above, the films were crystalline with typical cell constants of a=3.405 Å, c=5.609 Å. All the films showed a TiS 2 Raman pattern with bands at 335 and 380 cm −1. Energy-dispersive analysis by X-rays (EDAX) gave a Ti:S ratio of 1:2. The TiS 2 films were gold, highly reflective and showed semi-metal electrical conductivities. Scanning electron microscopy (SEM) showed a dense particulate morphology at low substrate temperatures (200–400 °C) and a needle-like mosaic at higher deposition temperatures. APCVD reaction of TiCl 4 and (CH 3) 3CSSC(CH 3) 3 at substrate temperatures of 250–400 °C produced TiS 3 and at 500–600 °C TiS 2 films. The TiS 3 films gave Raman bands at 557, 369, 297 and 172 cm −1, and a Ti:S ratio of 1:3 by EDAX.