CHARACTERIZATION OF TRIS (8-HYDROXYQUINOLINE) ALUMINUM (Alq3) FILM USING SPECTROSCOPIC ELLIPSOMETRY

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4353-4358 ◽  
Author(s):  
YONG JAI CHO ◽  
HYUN JONG KIM ◽  
WON CHEGAL ◽  
HYUN MO CHO ◽  
UN BONG BAEK ◽  
...  
Keyword(s):  
Band Gap ◽  
Spectroscopic Ellipsometry ◽  
Silicon Substrate ◽  
Optical Constants ◽  
Dispersion Function ◽  
Film Model ◽  
Data Inversion ◽  
A Value ◽  
Organic Sample

We have applied spectroscopic ellipsometry to obtain the optical constants, i.e., refractive indices (n) and extinction coefficients (k) of a thin tris (8-hydroxyquinoline) aluminum ( Alq 3) film evaporated on the top of 300-nm-thick SiO 2 layer on a silicon substrate. Using a spectroscopic ellipsometer we collected the ellipsometric data of Ψ and Δ at 3 incident angles of 65°, 70° and 75° and 226 energies of 1.5 eV to 6.0 eV. For the organic sample, we adopted a simple two-film model consisting of ambient/organic film/ SiO 2 film/silicon substrate. Using the multiple oscillators of Tauc-Lorentz (TL) dispersion function and the two-film model, we obtained the thickness of the Alq 3 film. By data inversion technique, the spectra of n and k for the Alq 3 film are calculated from measured Ψ and Δ at each photon energy when the film thickness is fixed to a value obtained by the TL dispersion fitting. The extrapolation of optical function near band gap yields the band gap of 2.64 eV for Alq 3 film.

Determination and Critical Assessment of the Optical Properties of Common Substrate Materials Used in III-V Nitride Heterostructures with Vacuum Ultraviolet Spectroscopic Ellipsometry

2001 ◽  
Vol 693 ◽  
Author(s):  
N.V. Edwards ◽  
O.P.A. Lindquist ◽  
L.D. Madsen ◽  
S. Zollner ◽  
K. Järrehdahl ◽  
...  
Keyword(s):  
Optical Properties ◽  
Dielectric Function ◽  
Spectroscopic Ellipsometry ◽  
Optical Constants ◽  
Vacuum Ultraviolet ◽  
Critical Assessment ◽  
Optical Transitions ◽  
Common Substrate ◽  
Materials Used

AbstractAs a first step toward enabling the in-line metrology of III-V nitride heterostructure and materials, we present the optical constants of the two common substrate materials over an unprecendented spectral range. Vacuum Ultraviolet spectroscopic ellipsometry (VUVSE) was used to obtain the optical constants for Al2O3 and the ordinary and extra-ordinary component of the dielectric function for both 4H- and 6H-SiC. The results are discussed in the context of anisotropy, polytypism, bandstructure, optical transitions, and preparation/characterization of abrupt surfaces, where appropriate.

Spectroscopic Ellipsometry Analysis of InGaN/GaN and AlGaN/GaN Heterostructures Using a Parametric Dielectric Function Model

1999 ◽  
Vol 595 ◽  
Author(s):  
J. Wagner ◽  
A. Ramakrishnan ◽  
H. Obloh ◽  
M. Kunzer ◽  
K. Köhler ◽  
...  
Keyword(s):  
Band Gap ◽  
Dielectric Function ◽  
Spectroscopic Ellipsometry ◽  
Composition Dependence ◽  
Band Gap Energy ◽  
Function Model ◽  
Gap Energy ◽  
The Individual ◽  
Gap Data

AbstractSpectroscopic ellipsometry (SE) has been used for the characterization of AlGaN/GaN and InGaN/GaN heterostructures. The resulting pseudodielectric function spectra were analyzed using a multilayer approach, describing the dielectric functions of the individual layers by a parametric oscillator model. From this analysis, the dielectric function spectra of GaN, AlxGa1−xN (x≤0.16), and In0.13Ga0.87N were deduced. Further, the dependence of the AlxGa1−xN band gap energy on the Al mole fraction was derived and compared with photoluminescence data recorded on the same material. The SE band gap data are compatible with a bowing parameter close to 1 eV for the composition dependence of the AlxGa1−xN gap energy. Finally, the parametric dielectric functions have been used to model the pseudodielectric function spectrum of a complete GaN/AlGaN/InGaN LED structure.

Optical Characterization of Graphene Oxide Films by Spectroscopic Ellipsometry

2016 ◽  
Vol 851 ◽  
pp. 199-204 ◽  
Author(s):  
Veronika Schmiedova ◽  
Jan Pospisil ◽  
Oldrich Zmeskal ◽  
Viliam Vretenar
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Graphene Oxide ◽  
Spectroscopic Ellipsometry ◽  
Inkjet Printing ◽  
Optical Characterization ◽  
Thermal Reduction ◽  
Visible Range ◽  
Dispersion Function

The paper deals with the study of optical properties of graphene oxide (GO) by inkjet printing. Defined structure of GO can be obtained by reducing of prepared layers either by heating or by UV radiation (rGO). The dispersion function for refractive index and extinction coefficient of GO and both rGO thin films were measured by spectroscopic ellipsometry in the wavelength range of 200 – 850 nm. Spectroscopic ellipsometry (SE) was used characterize the optical response of layer of GO reduced by UV and thermal reduction GO in visible range.

Characterization of Ion-Implanted Aluminum and Iron by Spectroscopic Ellipsometry

1990 ◽  
Vol 201 ◽  
Author(s):  
J. S. Brodkin ◽  
W. Franzen ◽  
R. J. Culbertson ◽  
J. M. Williams
Keyword(s):  
Aluminum Alloy ◽  
Spectroscopic Ellipsometry ◽  
Optical Constants ◽  
Chromium Ions ◽  
Non Destructive ◽  
Non Destructive Characterization ◽  
Ion Implanted

AbstractThe change in the optical constants of aluminum alloy and iron samples caused by implantation with nitrogen and chromium ions has been investigated by spectroscopic ellipsometry. The objective is to develop a method for simple, non-destructive characterization of ion-implanted metals.

Characterization of TFT-LCD and OLEDs Devices by Phase Modulated Spectroscopic Ellipsometry for Display Applications

2006 ◽  
Vol 965 ◽  
Author(s):  
Eric Teboul ◽  
Li Yan ◽  
Melanie Gaillet
Keyword(s):  
Spectroscopic Ellipsometry ◽  
Optical Constants ◽  
Complex Structure ◽  
Organic Light Emitting Diodes ◽  
Strong Anisotropy ◽  
Graded Materials ◽  
Light Emitting ◽  
Spectroscopic Ellipsometer ◽  
Organic Light

ABSTRACTSpectroscopic ellipsometry is one of the most accurate and reliable optical technique to characterize polymers, liquid crystals (LCs) and organic light emitting diodes (OLEDs). Because these devices are formed by complex structure including optical anisotropy, absorbing and graded materials, the correct use of spectroscopic ellipsometer required a combination of the proper choice of hardware and the appropriate ellipsometric model. In this work, we presents ellipsometric results obtained by a commercially available phase modulated spectroscopic ellipsometer (PMSE) on a full TFT-LCD structure characterized from UV to NIR. As expected, strong anisotropy and inhomogeneous optical properties were found respectively on LCs and ITO materials. We also presents measurements of film thickness and optical constants of each layer constituing an OLED structure

Characterization Of Amorphous Carbon Films Based On Carbon, Nitrogen, and hydrogen*.

1995 ◽  
Vol 415 ◽  
Author(s):  
H. Efstathiadis ◽  
Z. Akkerman ◽  
F. W. Smith
Keyword(s):  
Optical Constants ◽  
Chemical Vapor ◽  
Carbon Films ◽  
Amorphous Carbon Films ◽  
A Value ◽  
Energy Gaps ◽  
Free Energy Model ◽  
Nitrogen Alloy ◽  
Amorphous Hydrogenated Carbon

ABSTRACTA series of amorphous hydrogenated carbon-nitrogen alloy films (a-CxNyHz) has been prepared via plasma-enhanced chemical vapor deposition from mixtures of nitrogen and acetylene. It is found that as the ratio R=N2/C2H2 is increased from zero to 100, the nitrogen incorporation into the films is increasing while the deposition rate is decreasing for 0<R<10 and is saturating at a value of about 1.0 A/sec for 10<R<100. The absorption associated with the N-H stretching mode increases while that of the C-H stretching mode decreases with increase of R. The optical constants and the energy gaps of these films have also been determined. A free energy model previously developed for the prediction of the bonding in amorphous a-CxHyalloys is extended and applied here to a-CxNyHz. Predictions are presented for the bonding of tetrahedral C(sp3), trigonal C(sp2), linear C(sp1), pyramidal N(sp 3), trigonal N(sp 2), and linear N(sp1) atoms in the alloy, and the bonding of H to these atoms.

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