Growth and characterization of Ti-based films obtained from two selected precursors: H2O, TiCl4, Ti(N(CH3)2)4 or Al2(CH3)6 by the ALD method

Abstract

Ti-based films are extensively studied as a prospective material for several applications - for UV-protection, antibacterial coating and effective photocatalytic activity. This is because Ti-based TiO2 shows relatively high reactivity and chemical stability under ultraviolet light (λ < 387 nm), whose energy exceeds the band gap (in the range 3–4 eV) of the anatase crystalline phase. However, the efforts are focused on development of photocatalytic materials exhibiting high reactivity under visible light (λ > 400 nm). Such materials should utilize the main part of the solar spectrum, and if efficient, they should work even under poor illumination, for example upon interior lighting. In this work, we concentrated on optimization of Ti-based films. Films with different chemical compositions were deposited using the atomic layer deposition (ALD) method. These films were prepared using chemical reactions between listed precursors: H2O, TiCl4, Ti(N(CH3)2)4 and Al2(CH3)6. The selection of precursors and, consequently, the modification of the ALD Ti-based process allowed the deposition of thin films with quite different structural, optical and electrical properties.