[22p-E204-1~13] 6.3 Oxide electronics

▼ [22p-E204-3] Orthorhombic distortion and optoelectronic transport properties of rutile Nb:TiO₂ epitaxial films grown on M-plane sapphire substrates

〇(D)Binjie Chen¹, Yuqiao Zhang², Hiromichi Ohta³ (1.IST-Hokkaido U., 2.Jiangsu U., 3.RIES-Hokkaido U.)

Keywords:Epitaxial film, Titanium dioxide, Lattice distortion

Rutile and anatase TiO₂ are known as the important active materials of photocatalyst and the transparent electrode. However, there are several differences between them: the bandgap of the anatase phase is larger than that of the rutile phase, while the electron mobility of the anatase phase is higher than that of the rutile phase, due to the difference in the electronic structure. It is known that the crystal structure of TiO₂ film can be controlled by changing the substrate crystal; anatase phase is grown on (001) LaAlO₃ substrate and rutile phase is grown on sapphire substrate, probably due to the lattice matching. Since the electronic structure is determined by the crystal structure, adding lattice distortion is commonly used to modulate the electronic structure of a material. In this study, we focus on the modulation of the optoelectronic properties of rutile TiO₂ epitaxial films by introducing orthorhombic lattice distortion using an anisotropic in-plane lattice of M-plane sapphire substrate.