Search results for " implantation."
showing 10 items of 677 documents
Ion irradiation of AZO thin films for flexible electronics
2017
Aluminum doped Zinc oxide (AZO) is a promising transparent conductor for solar cells, displays and touch-screen technologies. The resistivity of AZO is typically improved by thermal annealing at temperatures not suitable for plastic substrates. Here we present a non-thermal route to improve the electrical and structural properties of AZO by irradiating the TCO films with O+ or Ar+ ion beams (30–350 keV, 3 × 1015–3 × 1016 ions/cm2) after the deposition on glass and flexible polyethylene naphthalate (PEN). X-ray diffraction, optical absorption, electrical measurements, Rutherford Backscattering Spectrometry and Atomic Force Microscopy evidenced an increase of the crystalline grain size and a …
Annealing reactions in lead implanted copper
2002
Abstract The terminal solubility of Pb in Cu is extremely low and does not exceed 0.09 at.% at 875 K. Ion implantation of lead ions at 100 keV into Cu single crystals produces metastable solutions. Annealing of the samples causes redistribution of the implanted atoms to equilibrium or near-equilibrium aggregate states which may be reflected in a change in the type of impurity lattice location in the host matrix. We have studied the effect of annealing on single crystalline Cu implanted at temperatures around 375 K with Pb to a concentration of a 1–2 at.%. Rutherford backscattering/channeling analysis and transmission electron microscopy of the as-implanted samples have shown that the implan…
Ion implantation effects in BaTiO3 single crystals
1991
Abstract Thermally controlled helium implantation has been used to produce planar waveguides in BaTiO3 without noticeable depoling effects in the samples. Profiles for the ordinary and extraordinary refractive index are deduced from optical mode measurements. No annealing procedure is required. We report the effects of different ion fluences and energies in the MeV range on the waveguide properties.
On the use of grazing-incidence small-angle X-ray scattering (GISAXS) in the morphological study of ion-implanted materials.
2004
Grazing-incidence small-angle X-ray scattering has become a widely used technique for the morphological analysis of surface systems. Here it is show how this technique can be applied to a buried system, like metallic clusters in glass obtained by ion implantation. The optimization of the data-collection geometry is described as well as the details of the quantitative data analysis. An experimental example on Cu + Au-implanted glasses shows the potentiality of the technique.
Radiation induced defects in SiO 2
2002
The main luminescent centers in SiO 2 films are the red luminescence R (650 v nm; 1.85 v eV) of the non-bridging oxygen hole center (NBOHC) and the twofold-coordinated (divalent) silicon with a blue B (460 v nm; 2.7 v eV) and a UV band (285 v nm; 4.4 v eV). Especially the latter ones are produced under irradiation, but from existing precursors assumed as silicon related oxygen deficient centers (SiODC). Therefore, in order to prove these models we compare a direct oxygen implantation with a direct silicon implantation into SiO 2 layers. The main result is: implanting oxygen increases the red band R but does not affect the blue band B. Silicon surplus increases the amplitude of the blue (B) …
Aesthetic perception of single implants placed in the anterior zone. A cross-sectional study
2016
Background: Several aesthetic indexes have been described to assess implant aesthetics. The aim of this study was to compare the aesthetic assessment made by dental professionals and students of single-tooth implants placed in the upper incisors. Material and Methods: A cross-sectional survey study using a subjective questionnaire to assess the aesthetics in 3 implant supported single-tooth cases in the anterior maxilla was performed. The interviewed subjects were divided into 4 groups: dentists with experience in implant treatment, dentists without experience in implants and 3rd and 5th year dental students. The questionnaire consisted of 2 visual analogue scales (VAS) to evaluate aestheti…
In vitro optical quality comparison of 2 trifocal intraocular lenses and 1 progressive multifocal intraocular lens.
2015
Purpose To evaluate the optical quality of 3 multifocal intraocular lenses (IOLs): the Mini Well Ready progressive multifocal aspheric IOL, the AT LISA trifocal diffractive IOL, and the Finevision full diffractive trifocal IOL. Setting University of Valencia, Valencia, Spain. Design Experimental study. Methods An instrument designed for measuring real-time modulation transfer function (MTF) and IOL power was used to measure the optical quality of each IOL for 3.0 mm and 4.5 mm apertures. This instrument measures both sagittal and tangential MTFs. The optical quality of each IOL was evaluated with the MTF, through-focus MTF, defocus tolerance, Strehl ratio MTF, and relative percentage of lig…
Optical Quality Comparison of Conventional and Hole-Visian Implantable Collamer Lens at Different Degrees of Decentering
2012
To compare the optical quality of implantable Collamer lens (ICL) with and without central hole (Hole ICL and conventional ICL) at different degrees of decentering.Experimental laboratory investigation.Wavefront aberrations of the -3, -6, and -12 diopter (D) V4b and -3, -6, and -12 D V4c ICLs were measured in 3 conditions-centered and decentered 0.3 and 0.6 mm-at 3-mm and 4.5-mm pupils. The root mean square of total higher order aberrations, trefoil, coma, tetrafoil, secondary astigmatism, and spherical aberration were evaluated. In addition, point spread function and simulated retinal images of ICLs were calculated from the wavefront aberrations for each ICL and all conditions of decenteri…
Assessing the in vitro optical quality of presbyopic solutions based on the axial modulation transfer function.
2016
Purpose To present a metric for assessing the in vitro optical quality of rotationally symmetrical optical elements based on volume calculation under the surface defined by the axial modulation transfer function (MTF). Setting University of Valencia, Valencia, Spain. Design Experimental study. Methods The metric volume under the axial MTF was used to assess the optical quality of 2 rotationally symmetrical multifocal intraocular lenses (IOLs) within various defocus intervals (0.50 diopter [D], 0.75 D, and 1.00 D) and at various spatial frequency intervals (7.5 cycles per degree [cpd], 15.0 cpd, and 30.0 cpd). Results The far focus of the bifocal IOL yielded higher volume values at all spati…
Predictability of intraocular lens power calculation after small-incision lenticule extraction for myopia
2019
PURPOSE To evaluate and compare the predictability of intraocular lens (IOL) power calculation after small-incision lenticule extraction (SMILE) for myopia and myopic astigmatism. SETTING Department of Ophthalmology, Philipps University of Marburg, Marburg, Germany. DESIGN Retrospective comparative case series. METHODS Preoperative evaluation included optical biometry using IOLMaster 500 and corneal tomography using Pentacam HR. The corneal tomography measurements were repeated at 3 months postoperatively. The change of spherical equivalent due to SMILE was calculated by the manifest refraction at corneal plane (SMILE-Dif). A theoretical model, involving the virtual implantation of the same…