Optical Characterization of Europium-Doped Calcium Fluoride Thin Films Grown on Silicon by Molecular Beam Epitaxy

1996 ◽  
Vol 446 ◽  
Author(s):  
X.M. Fang ◽  
W.K. Liu ◽  
W. Shan ◽  
T. Chatterjee ◽  
P.J. Mccann ◽  
...  
Keyword(s):  
Thin Films ◽  
Emission Spectra ◽  
Vibrational States ◽  
Zero Phonon Line ◽  
Phonon Line ◽  
X Ray ◽  
Integrated Intensity ◽  
Vibronic Sideband ◽  
Anti Stokes

AbstractPhotoluminescence measurements have been made on Eu-doped CaF2 thin films grown on Si(100) substrates. The dependence of the integrated intensity of both the zero-phonon line and the vibronic sideband on temperature and Eu concentration has been studied in the range of 10 – 300 K and 0.14 – 7.48 at. %, respectively. An anti-Stokes feature is visible in the emission spectra at 75 K, indicating a significant occupation of the excited vibrational states of Eu2+ by phonons before the transition at temperatures above 75 K. The integrated intensity of the vibronic sideband increases slightly as temperature increases. The solubility of Eu in CaF2 thin films grown on Si(100) is found to be somewhere around 4.05 at. % as confirmed by the increase of the line width of x-ray rocking curves and the decrease in the integrated intensity of the zero-phonon line with Eu concentration.

Temperature effect on the emission spectra of narrow band Mn4+phosphors for application in LEDs

2017 ◽  
Vol 19 (48) ◽  
pp. 32505-32513 ◽  
Author(s):  
Tadeusz Lesniewski ◽  
Sebastian Mahlik ◽  
Marek Grinberg ◽  
Ru-Shi Liu
Keyword(s):  
Temperature Effect ◽  
Narrow Band ◽  
Emission Spectra ◽  
Zero Phonon Line ◽  
Phonon Line ◽  
Anti Stokes ◽  
Line P

In narrow-band Mn4+phosphors, as the temperature increases, the intensity of both Stokes and anti-Stokes phonon sidebands increases with respect to zero-phonon line.

The Growth and Characterization of Germanium-Carbon Alloy Thin Films

1992 ◽  
Vol 270 ◽  
Author(s):  
Haojie Yuan ◽  
R. Stanley Williams
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Vacuum Chamber ◽  
Optical Band Gap ◽  
High Vacuum ◽  
Optical Absorption Spectroscopy ◽  
Alloy Thin Film ◽  
New Materials ◽  
X Ray

ABSTRACTThin films of pure germanium-carbon alloys (GexC1−x with x ≈ 0.0, 0.2, 0.4, 0.5, 0.6, 0.8, 1.0) have been grown on Si(100) and A12O3 (0001) substrates by pulsed laser ablation in a high vacuum chamber. The films were analyzed by x-ray θ-2θ diffraction (XRD), x-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), conductivity measurements and optical absorption spectroscopy. The analyses of these new materials showed that films of all compositions were amorphous, free of contamination and uniform in composition. By changing the film composition, the optical band gap of these semiconducting films was varied from 0.00eV to 0.85eV for x = 0.0 to 1.0 respectively. According to the AES results, the carbon atoms in the Ge-C alloy thin film samples has a bonding configuration that is a mixture of sp2 and sp3 hybridizations.

Broadband Coherent Anti-Stokes Raman Spectroscopy Characterization of Polymer Thin Films

2006 ◽  
Vol 60 (10) ◽  
pp. 1097-1102 ◽  
Author(s):  
Zachary D. Schultz ◽  
Marc C. Gurau ◽  
Lee J. Richter
Keyword(s):  
Thin Films ◽  
Raman Spectroscopy ◽  
Polymer Thin Films ◽  
Anti Stokes

Characterization of Permalloy Thin Films Via Variable Sample Exit Angle Ultrasoft X-Ray Fluorescence Spectrometry

1989 ◽  
pp. 261-268 ◽  
Author(s):  
George Andermann ◽  
Francis Fujiwara ◽  
T. C. Huang ◽  
J. K. Howard ◽  
N. Staud
Keyword(s):  
Thin Films ◽  
Fluorescence Spectrometry ◽  
Exit Angle ◽  
X Ray ◽  
Permalloy Thin Films

Structural and Optical Characterization of Zinc Telluride Thin Films

2013 ◽  
Vol 665 ◽  
pp. 254-262 ◽  
Author(s):  
J.R. Rathod ◽  
Haresh S. Patel ◽  
K.D. Patel ◽  
V.M. Pathak
Keyword(s):  
Thin Films ◽  
Extinction Coefficient ◽  
Nir Spectroscopy ◽  
Optical Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Evaporation Technique ◽  
Film Form ◽  
Znte Thin Films

Group II-VI compounds have been investigated largely in last two decades due to their interesting optoelectronic properties. ZnTe, a member of this family, possesses a bandgap around 2.26eV. This material is now a day investigated in thin film form due to its potential towards various viable applications. In this paper, the authors report their investigations on the preparation of ZnTe thin films using vacuum evaporation technique and their structural and optical characterizations. The structural characterization, carried out using an X-ray diffraction (XRD) technique shows that ZnTe used in present case possesses a cubic structure. Using the same data, the micro strain and dislocation density were evaluated and found to be around 1.465×10-3lines-m2and 1.639×1015lines/m2respecctively. The optical characterization carried out in UV-VIS-NIR region reveals the fact that band gap of ZnTe is around 2.2eV in present case. In addition to this, it was observed that the value of bandgap decreases as the thickness of films increases. The direct transitions of the carries are involved in ZnTe. Using the data of UV-VIS-NIR spectroscopy, the transmission coefficient and extinction coefficient were also calculated for ZnTe thin films. Besides, the variation of extinction coefficient with wavelength has also been discussed here.

scholarly journals Characterization of superconducting oxide thin films by X-ray diffraction.

1990 ◽  
Vol 37 (1) ◽  
pp. 141-144
Author(s):  
Tsunekazu Iwata ◽  
Akihiko Yamaji ◽  
Youichi Enomoto
Keyword(s):  
Thin Films ◽  
X Ray Diffraction ◽  
Oxide Thin Films ◽  
X Ray

Application of Aluminum Nitride Thin Film for Micromachined Ultrasonic Transducers

2005 ◽  
Vol 892 ◽  
Author(s):  
Qianghua Wang ◽  
Jianzeng Xu ◽  
Changhe Huang ◽  
Gregory W Auner
Keyword(s):  
Thin Films ◽  
Aluminum Nitride ◽  
Ultrasonic Transducers ◽  
X Ray Diffraction ◽  
Effective Coupling ◽  
Resonant Frequencies ◽  
X Ray ◽  
Coupling Factors ◽  
Sandwiched Structure

AbstractThis paper reports the fabrication and characterization of micromachined ultrasonic transducers (MUT) based on piezoelectric aluminum nitride (AlN) thin films. The MUT device is composed of an Al/AlN/Al sandwiched structure overlaid on top of a silicon (Si) diaphragm. X-ray diffraction (XRD) scan shows that highly c-axis oriented AlN (002) thin films have been grown on Al/Si(100) substrates. Electrical impedance of the MUT devices is analyzed as a function of frequency. The fundamental resonant frequencies of the devices are found in the range of 65-70 kHz, which are in approximation to the theoretical calculation. The effective coupling factors of the devices are also derived as 0.18.

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