Atomic Control of the SrTiO ₃ Crystal Surface

Abstract

The atomically smooth SrTiO(3) (100) with steps one unit cell in height was obtained by treating the crystal surface with a pH-controlled NH(4)F-HF solution. The homoepitaxy of SrTiO(3) film on the crystal surface proceeds in a perfect layer-by-layer mode as verified by reflection high-energy electron diffraction and atomic force microscopy. Ion scattering spectroscopy revealed that the TiO(2) atomic plane terminated the as-treated clean surface and that the terminating atomic layer could be tuned to the SrO atomic plane by homooepitaxial growth. This technology provides a well-defined substrate surface for atomically regulated epitaxial growth of such perovskite oxide films as YBa(2)Cu(3)O(7-delta).

Nanocrystalline Mesoporous Strontium Titanate as Photoelectrode Material for Photosensitized Solar Devices: Increasing Photovoltage through Flatband Potential Engineering

“…Recent work has suggested that the SrTiO 3 surface can be selectively altered through pH treatments to etch the more acidic TiO 2 or the more basic SrO, and future syntheses which minimize the SrOterminated surfaces may enhance dye adsorptance values and increase photocurrents and IPCE values. 26 Alternately, the sensitizer used has been optimized for anatase, and use of other sensitizers may lead to improved performance through better interfacial characteristics. Figure 6.…”

Materials science: Enter the oxides

“…In 1994, this problem was identified and solved for SrTiO 3 by Masashi Kawasaki, a materials scientist then at the Tokyo Institute of Technology, now at Tohoku University in Japan, who developed a pre-growth treatment involving various acids that strip the crystal substrate down to the desired atomic layer 10 . With this advance, says Kawasaki, "people could finally grow complex oxides".…”

Constructing oxide interfaces and heterostructures by atomic layer-by-layer laser molecular beam epitaxy

“…43 to produce atomically flat TiO 2 -terminated surface with one unit-cell-high steps. The (001) LaAlO 3 substrates used in this work were treated following the receipe in ref.…”