Structural, optical, and electrical properties of epitaxial titanium oxide thin films on LaAlO3 substrate

Abstract

Articles you may be interested inEffect of SnO2 concentration on the tuning of optical and electrical properties of ZnO-SnO2 composite thin films Electrical and optical properties of transparent conducting In4+xSn3−2xSbxO12 thin films J. Appl. Phys. 110, 033702 (2011); 10.1063/1.3605552Structure-related optical properties of ( Pb , La ) ( Zr , Ti ) O 3 thin films on indium tin oxide∕quartz substrates Titanium oxide thin films were prepared by pulsed-laser deposition on LaAlO 3 single crystal substrate at 700°C. Pure anatase films are obtained at high oxygen pressure ͑10 −1 mbar͒, while the rutile phase is evidenced at low oxygen pressure ͑10 −5 mbar͒ despite a large oxygen deficiency ͑O / Ti= 1.75͒. From asymmetric x-ray diffraction measurements, the in-plane epitaxial relationships be0tween the substrate and the titanium oxide phases are highlighted. Optical constants ͑refractive index n and extinction coefficient k͒ were deduced from ellipsometric measurements. The optical band gap energies of the anatase and rutile films are found to be 3.4 and 3.3 eV, respectively. Since the nearly stoichiometric anatase films are resistive ͑Ͼ10 3 ⍀ cm͒, the large oxygen deficiency in rutile films leads to noticeable increase in the conductivity due to the Ti 3+ species, which supply electrons in the conduction band. At low temperature ͑T Ͻ 200 K͒ the resistivity of rutile films versus temperature may be explained by a variable range hopping mechanism based on both two or three dimensional electron transfer between the Ti 3+ and Ti 4+ species.

Atomic-scale structure and electronic property of the LaAlO3/TiO2 interface

“…3͑a͒. The TiO 2 layers are found to have epitaxial orientation relationships ͑001͒ TiO 2 ʈ ͑001͒ LAO and ͓100͔ TiO 2 ʈ ͓100͔ LAO with substrate, in accordance with previous reports 16,40 and the above XRD analyses demonstrating strongly ͑001͒-oriented textures for both materials.…”

UV to NIR photon conversion in Nd-doped rutile and anatase titanium dioxide films for silicon solar cell application

“…Regarding XRD patterns, these differences could be explained by a better crystalline quality in R 200 rather than in R PC as the FWHM of (2 0 0) peak of R-TiO 2 is smaller than the other ones. In previous works [17,18], it has been demonstrated that R-or A-TiO 2 films grown on sapphire and LaAlO 3 substrates are strongly oriented according to the same out-of plane relationships evidenced in the present study and they are also epitaxied allowing for such films to be almost considered as like-single crystal. Despite its interesting structural properties, the A-TiO 2 films do not lead to intense PL emission due to the STE process.…”

Epitaxial growth of copper oxide films by reactive cross-beam pulsed-laser deposition

“…Indeed, the flux of oxygen atoms reaching the surface of the growing film depends upon the oxygen partial pressure (PO 2 ) in the ablation chamber and, consequently, the incorporation of oxygen atoms in oxide films may be strongly limited when PO 2 is decreased as it has been recently reported on the growth of oxygen deficient perovskite phase [12,13] or oxygen deficient titanium oxide [14,15]. In addition, the incorporation of oxygen in films may be increased by using an external source of plasma.…”