Hydrothermal growth and characterization of ZnO crystals

ZnO crystals with dimensions of 30 x 38 x 8 turn 3 have been grown by the hydrothermal method using a mixed solution of KOH, LiOH and H2O2. The growing rates for +c(0001) and -c(000 (1) over bar) were 0.17 and 0.09 mm/day, respectively. The crystal color was very light green for +c sector and dark brown for -c sector. For the +c sector, the resistivity at room temperature was 80 0 cm, the carrier concentration was about 10(4)/cm(3), and the mobility was about 100 cm(2)/Vs. The full-width at half-maximum (FWHM) of double axis X-ray rocking curve for the polished Zn face cut from +c sector was 45 arcsec. The photoluminescence (PL) spectrum and the absorption spectrum of +c part of the crystals at room temperature were also reported and discussed in this paper. (c) 2008 Elsevier B.V. All rights reserved.

Influence of oxygen plasma treatment on properties of ZrO2 films prepared by e-beam evaporation techniques

Zirconia films were prepared by e-beam evaporation, and oxygen plasma treatment was used to modify film properties. Spectrophotometry, x-ray diffractometry (XRD), and atomic force microscopy were used to characterize refractive index, extinction coefficient, rnicrostructure, and surface roughness, respectively. The experimental results indicate that both refractive index and extinction coefficient of the films were reduced slightly after oxygen plasma treatment, with the decrease of intrinsic stress and surface roughness. From XRD spectra, the intensity decrease of the T(110) diffraction peak was clearly observed after the treatment, which was caused by the restructuring of the film atoms. (C) 2008 Elsevier Ltd. All rights reserved.

Influence of oxygen post-treatment on laser-induced damage of antireflection coatings prepared by electron-beam evaporation and ion beam assisted deposition

Antireflection coatings at the center wavelength of 1053 nm were prepared on BK7 glasses by electron-beam evaporation deposition (EBD) and ion beam assisted deposition (IBAD). Parts of the two kinds of samples were post-treated with oxygen plasma at the environment temperature after deposition. Absorption at 1064 nm was characterized based on surface thermal lensing (STL) technique. The laser-induced damage threshold (LIDT) was measured by a 1064-nm Nd:YAG laser with a pulse width of 38 ps. Leica-DMRXE Microscope was applied to gain damage morphologies of samples. The results revealed that oxygen post-treatment could lower the absorption and increase the damage thresholds for both kinds of as-grown samples. However, the improving effects are not the same. (c) 2008 Elsevier B.V. All rights reserved.