Nanomechanical Properties of Titanium Oxide (TiO2) Grown by Atomic Layer Deposition

Abstract

Titanium oxide (TiO2) materials experienced increased attention and growth because of their use as electrode material in lithium rechargeable batteries and they also offer excellent photocatalytic properties due to their stability, nontoxicity, and superb photo catalytic activity. However their absorption of the visible light is restricted due to their wide band gap (3.2 eV). One way of improving their absorption capabilities to the visible light is by doping such wide band gaps semiconducting oxides. The N-doped TiO2 films prepared by sputtering showed noticeable visible light absorption at wavelengths of less than 500 nm due to the bandgap narrowing by mixing of N 2p states with O 2p states [1-3]. Many of the properties in these applications are strongly dependent on titanium oxide’s crystal morphology, surface area, and mechanical properties.TiO2 films of 200, 300, and 500, ALD cycles were deposited on p-type Si (100) substrates using Atomic layer deposition (ALD) technology. These films have been tested for structural, surface morphology, and nanomechanical properties using nanoindentation. The structural and surface properties will be explored using X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). We will discuss the influence of the deposition technique on the structure and properties of the films citing the superiority of the ALD technique that is particularly used in the fabrication of the films that are presented in this study. A field emission scanning electron microscopy (FE-SEM) image is shown in Figure 1. References 1- R. Asahi, T. Morikawa, T. Ohwaki, K. Aoki, and Y. Taga, Science, 293, 269 (2001).2- J. Li, Y. Qin, C. Jin, Y. Li, D. Shi, L. Schmidt-Mende, L. H. Gan, and J. H. Yang,bNanoscale, 5, 5009 (2013).3- C. X. Feng,G. Q.Xu, J. Lv,Q. M. Huang, Z. X. Zheng, andY. C.Wu, J. Electrochem. Soc, 160, H727 (2013).