Dey B., Choquet P., Valle N., Richard-Plouet M., Granier A., Bulou S.
Surface and Coatings Technology, vol. 516, art. no. 132759, 2025
This work investigates the growth and crystallization mechanisms of TiO<sub>2</sub> layers synthesized below 100 °C via pulsed Plasma-Enhanced Chemical Vapor Deposition using an Ar/O<sub>2</sub>/titanium tetraisopropoxide (TTiP) gas mixture. To do so, a comparison of the coating properties between continuous and pulsed waves (CW and PW) deposition conditions was done. At equal average power, PW discharge yielded more anatase crystallites and higher photocatalytic efficiency, with similar substrate temperature, composition, and growth rate. Experimental results are presented to clarify pulsed PECVD TiO<sub>2</sub> film growth from organotitanate precursors. To assess the interactions between the reactive oxygen species from the plasma discharge and TTiP precursor, the <sup>18</sup>O<sub>2</sub> labelling method was used. SIMS analysis revealed over 70 % <sup>18</sup>O incorporation, and possible enrichment mechanisms are proposed. It appears that, at equal average power, PW discharges promote the growth of TiO<sub>2</sub> layers thanks to a higher density of atomic oxygen and ions with kinetic energy over 30 eV.
