Near-Infrared (NIR) to Red and Green Up-Conversion Emission from Silica Sol−Gel Thin Films Made with La0.45Yb0.50Er0.05F3Nanoparticles, Hetero-Looping-Enhanced Energy Transfer (Hetero-LEET):  A New Up-Conversion Process

2007 ◽  
Vol 129 (3) ◽  
pp. 620-625 ◽  
Author(s):  
Sri Sivakumar ◽  
Frank C. J. M van Veggel ◽  
P. Stanley May
Keyword(s):  
Thin Films ◽  
Energy Transfer ◽  
Near Infrared ◽  
Sol Gel ◽  
Silica Sol ◽  
Conversion Process

scholarly journals Upconversion Luminescence of Silica–Calcia Nanoparticles Co-doped with Tm3+ and Yb3+ Ions

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 937
Author(s):  
Katarzyna Halubek-Gluchowska ◽  
Damian Szymański ◽  
Thi Ngoc Lam Tran ◽  
Maurizio Ferrari ◽  
Anna Lukowiak
Keyword(s):  
Energy Transfer ◽  
Near Infrared ◽  
Upconversion Luminescence ◽  
Sol Gel ◽  
Emission Spectra ◽  
Transmission Electron ◽  
Characteristic Emission ◽  
Diffraction Patterns ◽  
Size Of Particles ◽  
Average Size

Looking for upconverting biocompatible nanoparticles, we have prepared by the sol–gel method, silica–calcia glass nanopowders doped with different concentration of Tm3+ and Yb3+ ions (Tm3+ from 0.15 mol% up to 0.5 mol% and Yb3+ from 1 mol% up to 4 mol%) and characterized their structure, morphology, and optical properties. X-ray diffraction patterns indicated an amorphous phase of the silica-based glass with partial crystallization of samples with a higher content of lanthanides ions. Transmission electron microscopy images showed that the average size of particles decreased with increasing lanthanides content. The upconversion (UC) emission spectra and fluorescence lifetimes were registered under near infrared excitation (980 nm) at room temperature to study the energy transfer between Yb3+ and Tm3+ at various active ions concentrations. Characteristic emission bands of Tm3+ ions in the range of 350 nm to 850 nm were observed. To understand the mechanism of Yb3+–Tm3+ UC energy transfer in the SiO2–CaO powders, the kinetics of luminescence decays were studied.

Fabrication of photo-crosslinkable polymer/silica sol–gel hybrid thin films as versatile barrier films

2016 ◽  
Vol 38 ◽  
pp. 61-66 ◽  
Author(s):  
Joonwon Bae ◽  
Jiyeon Lee ◽  
Chul Soon Park ◽  
Oh Seok Kwon ◽  
Chang-Soo Lee
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Silica Sol ◽  
Barrier Films ◽  
Hybrid Thin Films

Energy transfer between semiconductor nanoparticles (ZnS or CdS) and Eu3+ ions in sol–gel derived ZrO2 thin films

2008 ◽  
Vol 30 (10) ◽  
pp. 1595-1602 ◽  
Author(s):  
G. Ehrhart ◽  
B. Capoen ◽  
O. Robbe ◽  
F. Beclin ◽  
Ph. Boy ◽  
...  
Keyword(s):  
Thin Films ◽  
Energy Transfer ◽  
Sol Gel ◽  
Semiconductor Nanoparticles

The Influencing Factors for the Thickness of Silica Sol-Gel Film by the Dip Coating Process

2014 ◽  
Vol 597 ◽  
pp. 165-169
Author(s):  
Jie Hong Lei ◽  
Ri Dong Zhang
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Refractive Index ◽  
Sol Gel ◽  
Dip Coating ◽  
Silica Sol ◽  
Coating Process ◽  
Power Functions ◽  
Withdrawal Speed ◽  
Gel Film

The porous sol-gel silica thin films were prepared on silicon substrate by the dip coating process. The surface roughness and microstructure of the film was measured by optical microscopy and AFM .Coating thickness and refractive index were measured by ellipsometry method. Influence of withdrawal speed and concentration of colloid was investigated for the thickness of silica. The relation of the thickness and withdrawal speed was fitted by the linear and power functions, and the results were analyzed and compared. It was found that the films with the same thickness prepared by different concentrations of colloid have different refractive indexes. The experimental results indicated that the thickness and refractive index of the film can be controlled by changing the withdrawal speed and colloid concentration.

Electrical Properties of Indium-Doped Zinc Oxide Nanostructures Doped at Different Dopant Concentrations

2015 ◽  
Vol 1109 ◽  
pp. 593-597
Author(s):  
M.F. Nasir ◽  
Mohd Hannas ◽  
Mohamad Hafiz Mamat ◽  
Mohamad Rusop
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Optical Properties ◽  
Electrical Properties ◽  
Near Infrared ◽  
Sol Gel ◽  
Zinc Oxide Nanostructures ◽  
Glass Substrates ◽  
In Doping ◽  
Coating Method

This project has been focused on the electrical and optical properties on the effect of Indium doped zinc oxide (ZnO) thin films at different dopant concentrations. These thin films were doped with different In dopant concentrations at 1 at%, 1.5 at%, 2 at%, 3 at%, 4 at% and 5 at% was selected as the parameter to optimize the thin films quality while the annealing temperature is fixed 500 oC. In doped ZnO solutions were deposited onto the glass substrates using sol-gel spin coating method. This project was involved with three phases, which are thin films preparation, deposition and characterization. The thin films were characterized using Current Voltage (I-V) measurement and UV-Vis-NIR spectrophotometer for electrical properties and optical properties. The electrical properties show that the resistivity is the lowest at 4 at% In doping concentration which is 8.27× 103Ωcm-1The absorption coefficient spectrum obtained from UV-Vis-NIR spectrophotometer measurement shows all films exhibit very low absorption in the visible (400-800nm) and near infrared (NIR) (>800nm) range but exhibit high absorption in the UV range.

Cooperative energy transfer in Yb3+–Tb3+ codoped silica sol-gel glasses

2001 ◽  
Vol 89 (5) ◽  
pp. 2520-2524 ◽  
Author(s):  
I. R. Martı́n ◽  
A. C. Yanes ◽  
J. Méndez-Ramos ◽  
M. E. Torres ◽  
V. D. Rodrı́guez
Keyword(s):  
Energy Transfer ◽  
Sol Gel ◽  
Silica Sol ◽  
Gel Glasses ◽  
Cooperative Energy

scholarly journals Determination of growth kinetics and size dependent structural, morphological, optical characteristics of sol-gel derived silica nanoparticles in silica matrix

2019 ◽  
Vol 37 (1) ◽  
pp. 16-24
Author(s):  
Bengü Özuğur Uysal ◽  
Fatma Z. Tepehan
Keyword(s):  
Thin Films ◽  
Silica Nanoparticles ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Silica Film ◽  
Silica Sol ◽  
Nano Silica ◽  
Silica Films ◽  
Annealing Temperatures ◽  
Silica Thin Films

AbstractNanocomposite silica thin films made using the sol-gel method were studied. The nano-silica films were prepared using a mixture of tetraethyl orthosilicate (TEOS), deionized water, ethanol, and ammonia solution. To control the growth of the particles inside the film, the nanocomposite silica film was prepared using a mixture of the nano-silica sol and the silica sol. The change in the particle size with the heat treatment temperature ranging from 450 °C to 1100 °C was investigated. X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), NKD (refractive index-N, extinction coefficient-K, and thickness-D) and ultraviolet-visible (UV-Vis) spectrophotometry were used for characterization purposes. The XRD studies showed that the nano-silica thin films were amorphous at all annealing temperatures except for 1100 °C. The_-cristobalite crystal structure formed at the annealing temperature of 1100 °C. Optical parameters, such as refractive indices and extinction coefficients, were obtained using the NKD analyzer with respect to the annealing temperature of the films. The activation energy and enthalpy of the nanocomposite silica film were evaluated as 22.3 kJ/mol and 14.7 kJ/mol, respectively. The cut-off wavelength values were calculated by means of extrapolation of the absorbance spectra estimated using the UV-Vis spectroscopy measurements. A red shift in the absorption threshold of the nanocomposite silica films indicated that the size of the silica nanoparticles increased with an increase of the annealing temperatures from 450 °C to 900 °C, and this confirms the quantum confinement effect in the nanoparticles.

Sign in / Sign up

Export Citation Format

Share Document