Parametric modeling of the dielectric function and identification of the critical point of a CdMgTe alloy in the vacuum ultraviolet spectral range

ABSTRACTA modified critical point model dielectric function for graphene is derived here and used to analyze spectroscopic ellipsometry data obtained over a wide spectral range from 3 to 9 eV. Critical point and exciton resonance energies are extracted and discussed. Our findings indicate that epitaxial graphene on SiC to exhibits equivalent exciton behavior to that of suspended graphene. We further apply our model dielectric function to evaluate dielectric function data for highly oriented pyrolytic graphite reported in the literature. Excellent agreement is found between the critical point model developed here and the literature data even for the low energy spectral range up to 1 eV.

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Critical point transitions of wurtzite AlN in the vacuum–ultraviolet spectral range

Applied Physics Letters ◽

10.1063/1.1762694 ◽

2004 ◽

Vol 84 (24) ◽

pp. 4866-4868 ◽

Cited By ~ 12

Author(s):

J. Chen ◽

W. Z. Shen ◽

H. Ogawa ◽

Q. X. Guo

Keyword(s):

Critical Point ◽

Spectral Range ◽

Vacuum Ultraviolet

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IR-VUV Dielectric Function of Al1−xInxN determined by Spectroscopic Ellipsometry

MRS Proceedings ◽

10.1557/proc-639-g6.13 ◽

2000 ◽

Vol 639 ◽

Author(s):

A. Kasic ◽

M. Schubert ◽

B. Rheinländer ◽

J. Off ◽

F. Scholz ◽

...

Keyword(s):

Dielectric Function ◽

Spectral Range ◽

Spectroscopic Ellipsometry ◽

Vacuum Ultraviolet ◽

Phonon Mode ◽

Film Growth ◽

Mode Frequency ◽

Buffer Layers ◽

Mid Infrared ◽

Theoretical Predictions

ABSTRACTSpectroscopic Ellipsometry from the mid-infrared (mid-ir) to the vacuum-ultraviolet (vuv) spectral range (350 cm−1 … 8.8 eV) is used to study the optical properties of hexagonal MOVPE-grown Al1−xInxN films for 0.11 ≤ × ≤ 0.21. The AlInN E1(TO) phonon shows a onemode behavior in contrast to recent theoretical predictions [H. Grille, Ch. Schnittler, and F. Bechstedt, Phys. Rev. B 61, 6091 (2000)]. Approximately 120 nm thick Al1−xInxN films grown on slightly compressively strained hexagonal GaN buffer layers reveal the influence of in-plane strain on the E1(TO) phonon mode frequencies. Al1−xInxN deposited directly on [0001] sapphire substrate possesses E1(TO) mode frequency which indicate fully relaxed film growth. For highquality Al0.890In0.110N one A1(LO) phonon mode was observed. Furthermore, we present the complex dielectric function of hexagonal Al0.872In0.128N from the mid-ir to vuv spectral range.

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Temperature dependent dielectric function in the near-infrared to vacuum-ultraviolet ultraviolet spectral range of alumina and yttria stabilized zirconia thin films

Journal of Applied Physics ◽

10.1063/1.4844515 ◽

2013 ◽

Vol 114 (22) ◽

pp. 223509 ◽

Cited By ~ 2

Author(s):

R. Schmidt-Grund ◽

T. Lühmann ◽

T. Böntgen ◽

H. Franke ◽

D. Opper ◽

...

Keyword(s):

Thin Films ◽

Dielectric Function ◽

Spectral Range ◽

Near Infrared ◽

Vacuum Ultraviolet ◽

Yttria Stabilized Zirconia ◽

Stabilized Zirconia ◽

Temperature Dependent

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Electronic transitions and dielectric function tensor of a YMnO3 single crystal in the NIR-VUV spectral range

RSC Advances ◽

10.1039/c4ra05036c ◽

2014 ◽

Vol 4 (63) ◽

pp. 33549-33554 ◽

Cited By ~ 6

Author(s):

Rüdiger Schmidt-Grund ◽

Steffen Richter ◽

Stefan G. Ebbinghaus ◽

Michael Lorenz ◽

Carsten Bundesmann ◽

...

Keyword(s):

Single Crystal ◽

Critical Point ◽

Dielectric Function ◽

Spectral Range ◽

Band Gaps ◽

Electronic Transitions ◽

Band Absorption

The dielectric function tensor elements of an YMnO3 single crystal yield M0 critical point like band-band absorption with discrete spectrally localized Lorentzian transitions within the band gaps.

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From Semiconductor to Metal in a Flash: Observing Ultrafast Laser-Induced Phase Transformations

MRS Proceedings ◽

10.1557/proc-481-395 ◽

1997 ◽

Vol 481 ◽

Cited By ~ 3

Author(s):

J. P. Callan ◽

A. M.-T. Kim ◽

L. Huangt ◽

E. N. Glezer ◽

E. Mazur

Keyword(s):

Phase Transformations ◽

Dielectric Function ◽

Spectral Range ◽

Laser Excitation ◽

Spectroscopic Technique ◽

Ultrafast Laser ◽

Lattice Heating ◽

Fs Laser

ABSTRACTWe use a new broadband spectroscopic technique to measure ultrafast changes in the dielectric function of a material over the spectral range 1.5–3.5 eV following intense 70-fs laser excitation. The results reveal the nature of the phase transformations which occur in the material following excitation. We studied the response of GaAs and Si. For GaAs, there are three distinct regimes of behavior as the pump fluence is increased — lattice heating, lattice disordering, and a semiconductor-to-metal transition.

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