Department of Chemistry, Graduate School of Science, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
ACS Nano. 2014 Jun 24;8(6):6145-50. doi: 10.1021/nn501563j. Epub 2014 May 27.
We developed a technique to fabricate oxide thin films with uniaxially controlled crystallographic orientation and lateral size of more than micrometers on amorphous substrates. This technique is lateral solid-phase epitaxy, where epitaxial crystallization of amorphous precursor is seeded with ultrathin oxide nanosheets sparsely (≈10% coverage) deposited on the substrate. Transparent conducting Nb-doped anatase TiO2 thin films were fabricated on glass substrates by this technique. Perfect (001) orientation and large grains with lateral sizes up to 10 μm were confirmed by X-ray diffraction, atomic force microscopy, and electron beam backscattering diffraction measurements. As a consequence of these features, the obtained film exhibited excellent electrical transport properties comparable to those of epitaxial thin films on single-crystalline substrates. This technique is a versatile method for fabricating high-quality oxide thin films other than anatase TiO2 and would increase the possible applications of oxide-based thin film devices.
我们开发了一种在非晶衬底上制备具有单轴控制结晶方向和大于微米级的横向尺寸的氧化物薄膜的技术。该技术是横向固相外延，其中非晶前驱体的外延结晶是通过在衬底上稀疏（≈10%覆盖率）沉积超薄氧化物纳米片来引发的。通过该技术在玻璃衬底上制备了透明导电 Nb 掺杂锐钛矿 TiO2 薄膜。X 射线衍射、原子力显微镜和电子背散射衍射测量证实了完美（001）取向和具有高达 10 μm 横向尺寸的大晶粒。由于这些特点，所得到的薄膜表现出与单晶衬底上的外延薄膜相当的优异的电输运性能。该技术是一种通用的方法，可用于制备除锐钛矿 TiO2 以外的高质量氧化物薄膜，并将增加氧化物基薄膜器件的可能应用。
