Atomic/molecular layer deposited thin-film alloys of Ti-4,4′- oxydianiline hybrid-TiO _2 with tunable properties

摘要

By combining atomic layer deposition (ALD) and molecular layer deposition (MLD) thin-film techniques, the latter being a variant of the former in which organic precursors are used, it is possible to deposit thin films containing precisely controlled portions of inorganic and organic constituents. This in turn enables the adjustment of material properties by changing the number of ALD and MLD cycles applied during the deposition. In this work, the properties of such thin-film "alloys" prepared by varying the portions of Ti-4,4′-oxydianiline (Ti-ODA) inorganic-organic hybrid and TiO _2 in the structure were investigated. The films were deposited at 280 °C using TiCl _4 and water as precursors for TiO _2, and TiCl _4 and ODA for the Ti-ODA hybrid. The results demonstrate excellent tunability of the film properties such as degree of crystallinity, roughness, refractive index, and hardness depending on the relative number of TiO _2 and Ti-ODA cycles employed.