scholarly journals Optical band gap and infrared phonon modes of (La_029Sr_071)(Al_065Ta_036)O_3 (LSAT) single crystal from infrared to ultraviolet range spectroscopic ellipsometry

2016 ◽  
Vol 6 (10) ◽  
pp. 3210 ◽  
Author(s):  
A. Barnes ◽  
H. Haneef ◽  
D. G. Schlom ◽  
N. J. Podraza
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Osiekowicz ◽  
D. Staszczuk ◽  
K. Olkowska-Pucko ◽  
Ł. Kipczak ◽  
M. Grzeszczyk ◽  
...  

AbstractThe temperature effect on the Raman scattering efficiency is investigated in $$\varepsilon$$ ε -GaSe and $$\gamma$$ γ -InSe crystals. We found that varying the temperature over a broad range from 5 to 350 K permits to achieve both the resonant conditions and the antiresonance behaviour in Raman scattering of the studied materials. The resonant conditions of Raman scattering are observed at about 270 K under the 1.96 eV excitation for GaSe due to the energy proximity of the optical band gap. In the case of InSe, the resonant Raman spectra are apparent at about 50 and 270 K under correspondingly the 2.41 eV and 2.54 eV excitations as a result of the energy proximity of the so-called B transition. Interestingly, the observed resonances for both materials are followed by an antiresonance behaviour noticeable at higher temperatures than the detected resonances. The significant variations of phonon-modes intensities can be explained in terms of electron-phonon coupling and quantum interference of contributions from different points of the Brillouin zone.


2015 ◽  
Vol 6 (12) ◽  
pp. 7305-7310 ◽  
Author(s):  
G. Grancini ◽  
V. D'Innocenzo ◽  
E. R. Dohner ◽  
N. Martino ◽  
A. R. Srimath Kandada ◽  
...  

Structural inhomogeneity on a micrometer-scale across a CH3NH3PbI3 single crystal is responsible for a local modulation of the optical band gap, which is also highly sensitive to humidity.


2018 ◽  
Vol 122 (51) ◽  
pp. 29464-29469
Author(s):  
Keyang Zhao ◽  
Fanming Huang ◽  
Chen-Min Dai ◽  
Wenwu Li ◽  
Shi-You Chen ◽  
...  

2019 ◽  
Vol 18 (01) ◽  
pp. 1850013 ◽  
Author(s):  
Maryam Motallebi Aghgonbad ◽  
Hassan Sedghi

In the present work, pure and Fe-doped ZnO thin films were deposited on glass substrates by sol–gel method. Zinc acetate and iron nitrate were used as the starting material and dopant source, respectively. The concentration of Fe doping was 6[Formula: see text]at.% and 8[Formula: see text]at.%. The optical and electronic properties of pure and Fe-doped ZnO thin films such as refraction index, extinction coefficient, dielectric function and optical band gap energy of the layers were obtained by spectroscopic ellipsometry method in the wavelength range of 300–900[Formula: see text]nm. The incidence angle of the layers kept 70[Formula: see text]. Also data obtained by Kramers–Kronig relations were used for comparison. The influence of Fe-doping concentration on the optical and electronic properties of thin films was studied. The transmittance data of ZnO thin films showed that 6[Formula: see text]at.% Fe-doped ZnO thin film has the highest transmittance value. Dielectric function of pure ZnO films was found to be higher compared with Fe-doped ones. Also it can be deduced from the results that Fe doping influences the optical band gap energy of thin films.


2008 ◽  
Vol 43 (6) ◽  
pp. 670-673 ◽  
Author(s):  
S. Krishnan ◽  
C. Justin Raj ◽  
S. Dinakaran ◽  
S. Jerome Das

2012 ◽  
Vol 7 (3) ◽  
pp. 290-294
Author(s):  
G. Shankar ◽  
G. Anbazhagan ◽  
P.S. Joseph ◽  
T. Balakrishn

2020 ◽  
Vol 109 ◽  
pp. 110351 ◽  
Author(s):  
Indranil Bhaumik ◽  
M. Soharab ◽  
R. Bhatt ◽  
A. Saxena ◽  
S. Sah ◽  
...  

2010 ◽  
Vol 654-656 ◽  
pp. 1764-1767 ◽  
Author(s):  
Kateryna Bazaka ◽  
Mohan V. Jacob

This study presents the effect of iodine doping on optical and surface properties of polyterpenol thin films deposited from non-synthetic precursor by means of plasma polymerisation. Spectroscopic ellipsometry studies showed iodine doping reduced the optical band gap from 2.82 eV to 1.50 eV for pristine and doped samples respectively. Higher levels of doping notably reduced the transparency of films, an issue if material is considered for applications that require high transparency. Contact angle studies demonstrated higher hydrophilicity for films deposited at increased doping levels, results confirmed by XPS Spectroscopy and FTIR. Doping had no significant effect on the surface profile or roughness of the film.


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