期刊
JOURNAL OF MATERIALS RESEARCH
卷 28, 期 13, 页码 1669-1679出版社
CAMBRIDGE UNIV PRESS
DOI: 10.1557/jmr.2013.42
关键词
-
资金
- U.S. National Science Foundation [0803663]
- Direct For Mathematical & Physical Scien
- Division Of Materials Research [0803663, 1304607] Funding Source: National Science Foundation
We have investigated the formation of the rutile and the anatase polymorphs of TiO2, with emphasis on epitaxial growth characteristics, and defect content as a function of laser and substrate variables. X-ray diffraction (XRD) studies revealed that the rutile phase is more stable at higher substrate temperatures and lower oxygen pressures; in contrast, decreasing the temperature and increasing the oxygen pressure gave rise to formation of anatase. Epitaxial rutile films with a <100] orientation were obtained at 450 degrees C using the pressure of 5 x 10(-4) Torr, and laser energy of 3.5-4.0 J/cm(2). The epitaxial relationship, determined by 2 theta-theta and phi scan of XRD and confirmed by transmission electron microscopy (TEM) diffraction patterns, was shown to be rutile(100)parallel to sapphire(0001), rutile[001]parallel to sapphire[10<(1)over bar>0] and rutile[010]parallel to sapphire[1 (2) over bar 10]. An atomically sharp interface between the rutile epitaxial film and the sapphire substrate was observed in the scanning transmission electron microscopy (STEM) images. The films exhibited a transmittance of 75-90% over the visible region. The absorption edge was observed to shift toward longer wave lengths at higher deposition temperatures or lower pressures. X-ray photoelectron spectroscopy and photoluminescence results showed that concentration of lattice point defects, namely oxygen vacancies and titanium interstitials, increased at lower oxygen pressures. Formation of nanostructured films with a surface roughness of -1.5-13.1 nm was confirmed by atomic force microscopy investigations.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据