Pyrolysis of Titanicone Molecular Layer Deposition Films as Precursors for Conducting TiO2/Carbon Composite Films

Titanium alkoxide films known as “titanicones” were grown using molecular layer deposition (MLD) techniques using the sequential exposure of TiCl 4 and glycerol. These titanicone MLD films were then pyrolyzed under argon to yield conducting TiO 2 /carbon composite films. The Raman spectra of the pyrolyzed titanicone films revealed the characteristic “D” and “G” peaks associated with sp 2 -graphitic carbon. X-ray diffraction analysis of the pyrolyzed titanicone films displayed the signatures for anatase and rutile TiO 2 after heating to 600 °C and then only rutile TiO 2 after heating to 900 °C. X-ray photoelectron depth profiling of the pyrolyzed titanicone films showed that the carbon was distributed throughout the film and began to segregate to the surface after heating to 900 °C. The sheet resistance of the pyrolyzed titanicone films dropped dramatically versus pyrolysis temperature and reached a minimum sheet resistance of 2.2 × 10 4 Ω/□ after heating to 800 °C. On the basis of the measured film thickness of 88 nm, the resistivity of the pyrolyzed titanicone film after heating to 800 °C was ρ = 0.19 Ω cm. Segregation of other hybrid organic–inorganic films into sp 2 -graphitic carbon and metal oxide domains after pyrolysis under argon was also observed for alucone films and various metalcone films based on Zn, Zr, Hf, and Mn. The conducting TiO 2 /carbon composite films and other metal oxide/carbon composite films could have important electrochemical applications as electrodes for Li ion batteries or pseudocapacitance supercapacitors.