Intrinsic electric fields and Raman spectra of III-V nitride wurtzite semiconductor heterostructures

1999 ◽  
Vol 59 (8) ◽  
pp. 5799-5805 ◽  
Author(s):  
D. Coffey ◽  
N. Bock
Keyword(s):  
Raman Spectra ◽  
Electric Fields ◽  
Semiconductor Heterostructures

Ab initio spectroscopy of water under electric fields

2019 ◽  
Vol 21 (38) ◽  
pp. 21205-21212 ◽  
Author(s):  
Giuseppe Cassone ◽  
Jiri Sponer ◽  
Sebastiano Trusso ◽  
Franz Saija
Keyword(s):  
Ab Initio ◽  
Raman Spectra ◽  
Electric Fields ◽  
Liquid Water ◽  
High Frequency ◽  
Water Structure ◽  
Ir And Raman Spectra ◽  
Bulk Liquid ◽  
Librational Mode ◽  
Ir And Raman

IR and Raman spectra of bulk liquid water under intense electric fields reveal the contraction of both spectra and the onset of a novel high-frequency librational mode band. Moreover, the water structure evolves toward “ice-like” arrangements.

Raman spectra of lithium sulfate crystal in strong electric fields

2002 ◽  
Vol 353 (3-4) ◽  
pp. 270-274 ◽  
Author(s):  
A.R. Aliev ◽  
M.M. Gafurov ◽  
I.R. Akhmedov
Keyword(s):  
Raman Spectra ◽  
Electric Fields ◽  
Lithium Sulfate ◽  
Strong Electric Fields ◽  
Sulfate Crystal

Effects of Pulsed Electric Fields on Phospholipid Molecular Conformation by Raman Spectra

2011 ◽  
Vol 140 ◽  
pp. 329-333
Author(s):  
Xiao Jia ◽  
Xin An Zeng
Keyword(s):  
Raman Spectra ◽  
Electric Fields ◽  
Molecular Conformation ◽  
Control Sample ◽  
Pulsed Electric Fields ◽  
Hydrocarbon Chain ◽  
Conformation Changes ◽  
Choline Group ◽  
Intensity Ratios ◽  
Sterilization Mechanism

In order to study the sterilization mechanism of pulsed electric fields（PEF） on microorganisms and the interaction between PEF conditions and cell membrane composed of phospholipids, the authors studied the phospholipid molecular conformation changes under various electric fields strength treatments using Raman spectra. It was demonstrated from the Raman spectra that there was little influence of PEF on the conformation of O-C-C-N+ backbone in the choline group of phospholipid. The intensity ratios of I1096/I1062 and I1096/I1126 represented the gauche/ trans ratioof C-C vibrations, but the first was increased directly, while the other one was increased firstly and then decreased with increasing electric fields strengths but the ratio was still higher than that of the control sample. I2885/I2850 represeted order/ disorder of chain-chain interactions which was decreased with increasing electric fields strengths. It was indicated that the intermolecular disordering in hydrocarbon chain of the lipid lattice was increased and the membrane fluidity was enhanced after PEF treatments.

scholarly journals A Theoretical Treatment of THz Resonances in Semiconductor GaAs p–n Junctions

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2412 ◽  
Author(s):  
Mohsen Janipour ◽  
I. Burc Misirlioglu ◽  
Kursat Sendur
Keyword(s):  
Dielectric Function ◽  
Electric Fields ◽  
Semiconductor Heterostructures ◽  
Theoretical Treatment ◽  
Low Loss ◽  
Depletion Zone ◽  
Charge Densities ◽  
As Doping ◽  
Effective Masses ◽  
Spatially Varying

Semiconductor heterostructures are suitable for the design and fabrication of terahertz (THz) plasmonic devices, due to their matching carrier densities. The classical dispersion relations in the current literature are derived for metal plasmonic materials, such as gold and silver, for which a homogeneous dielectric function is valid. Penetration of the electric fields into semiconductors induces locally varying charge densities and a spatially varying dielectric function is expected. While such an occurrence renders tunable THz plasmonics a possibility, it is crucial to understand the conditions under which propagating resonant conditions for the carriers occur, upon incidence of an electromagnetic radiation. In this manuscript, we derive a dispersion relation for a p–n heterojunction and apply the methodology to a GaAs p–n junction, a material of interest for optoelectronic devices. Considering symmetrically doped p- and n-type regions with equal width, the effect of certain parameters (such as doping and voltage bias) on the dispersion curve of the p–n heterojunction were investigated. Keeping in sight the different effective masses and mobilities of the carriers, we were able to obtain the conditions that yield identical dielectric functions for the p- and n-regions. Our results indicated that the p–n GaAs system can sustain propagating resonances and can be used as a layered plasmonic waveguide. The conditions under which this is feasible fall in the frequency region between the transverse optical phonon resonance of GaAs and the traditional cut-off frequency of the diode waveguide. In addition, our results indicated when the excitation was slightly above the phonon resonance frequency, the plasmon propagation attained low-loss characteristics. We also showed that the existence or nonexistence of the depletion zone between the p- and n- interfaces allowed certain plasmon modes to propagate, while others decayed rapidly, pointing out the possibility for a design of selective filters.

scholarly journals Raman spectra studies on (Ba,Sr)TiO3 ceramics under dc electric fields

2013 ◽  
Vol 62 (23) ◽  
pp. 237702
Author(s):  
Zhang Qi-Wei ◽  
Zhai Ji-Wei ◽  
Yue Zhen-Xing
Keyword(s):  
Raman Spectra ◽  
Electric Fields ◽  
Dc Electric Fields
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