Construction of TiO2/Si Heterostructure by Nanoepitaxial Growth of Anatase-type TiO2

Nearly defect-free interfaces can be formed using two lattice-matched semiconductors and nanoepitaxial growth methods that can be controlled at the atomic level. In this work, the nanoepitaxy of anatase-type TiO(2)on crystalline silicon substrates for fabricating TiO2/Si heterogeneous interface is demonstrated by combining self-assembly and hydrothermal methods. Solid-phase nanoepitaxy is formed in this heterogeneous interface according to the crystal type and crystal lattice matching between anatase-type TiO2 and crystalline silicon. X-ray diffraction (XRD) and crystal symmetry indicate that the nanoepitaxy growth of anatase-type TiO2 on the Si (001) plane is (001) plane. Anatase-type TiO2 atoms are directly connected with Si atoms. Inconsiderable SiO2 exists between anatase-type TiO2 and crystalline silicon substrate. These interfaces could promote the transfer rate of carriers and decrease the recombination rate of hole electron pairs. This evidence is confirmed by comparison with rutile-type TiO2, which could not be grown on Si substrate due to the mismatching crystal lattice parameter. The rutile-type TiO2 can be removed easily in ultrasonic condition.