Flexible Modulation of Electronic Band Structures of Wide Band Gap GaN Semiconductors Using Bioinspired, Nonbiological Helical Peptides

2017 ◽  
Vol 28 (2) ◽  
pp. 1704034 ◽  
Author(s):  
Sven Mehlhose ◽  
Nataliya Frenkel ◽  
Hirotaka Uji ◽  
Sara Hölzel ◽  
Gesche Müntze ◽  
...  
Keyword(s):  
Band Gap ◽  
Wide Band ◽  
Wide Band Gap ◽  
Band Structures ◽  
Electronic Band ◽  
Helical Peptides ◽  
Electronic Band Structures

Electronic Structure of Wide-Band-Gap Chalcopyrites

1992 ◽  
Vol 281 ◽  
Author(s):  
A. Petukhov ◽  
W. R. L. Lambrecht ◽  
B. Segall
Keyword(s):  
Electronic Structure ◽  
Band Gap ◽  
Structural Parameters ◽  
Wide Band ◽  
Orbital Method ◽  
Wide Band Gap ◽  
Electronic Band ◽  
Lattice Constants ◽  
Cohesive Energies ◽  
Electronic Band Structures

ABSTRACTElectronic band structures, equilibrium lattice constants and structural parameters, cohesive energies, and bulk moduli calculated by means of the linear-muffin-tin orbital method are presented for BeSiN2, MgSiN2 and MgSiP2 chalcopyrites. The relationships of these compounds to the “parent” III-V compounds are clarified.

scholarly journals OPTICAL AND ELECTRONIC PROPERTIES OF M2Si (M = Mg, Ca, Sr) GROWN BY REACTIVE DEPOSITION TECHNIQUE

2010 ◽  
Vol 24 (19) ◽  
pp. 3693-3699 ◽  
Author(s):  
JUNHUA HU ◽  
AKIHIKO KATO ◽  
TAIZOH SADOH ◽  
YOSHUHITO MAEDA ◽  
K. N. GALKIN ◽  
...  
Keyword(s):  
Optical Property ◽  
Band Gap ◽  
Density Functional ◽  
Energy Calculation ◽  
Band Structures ◽  
Electronic Band ◽  
Si Substrates ◽  
Optical And Electronic Properties ◽  
Plane Wave Basis Functions ◽  
Electronic Band Structures

Single phase M 2 Si ( M = Mg , Ca , Sr ) silicides were grown using Si substrates, by thermal treatment of the substrates in the vapors of the metallic sources, M , and the electronic structures and optical property of the silicides were investigated. The electronic band structures of the silicides were calculated using the first-principles total-energy calculation program in pseudopotential schemes with plane-wave basis functions. The calculated optical reflectance spectra were also deduced from the theoretical band structures, and roughly agreed with the experimental results except for the low reflectance intensity around 2 eV. This suggests that the energy band gap of the silicides roughly agree with the calculated values of 0.15, 0.31 and 0.35 eV for Mg 2 Si , Ca 2 Si and Sr 2 Si , respectively, within the underestimation of the band gap by the density functional calculation. The optical property of the silicides is also discussed in relation to the morphological structures of the silicides.

Electronic Structures of Wide Band-Gap (AlN)m(GaN)n[001] Superlattices

1995 ◽  
Vol 395 ◽  
Author(s):  
Z.-J. Tian ◽  
M.W.C. Dharma-Wardana ◽  
L.J. Lewis
Keyword(s):  
Band Gap ◽  
Electronic Band Structure ◽  
Wide Band ◽  
Orbital Method ◽  
Full Potential ◽  
Wide Band Gap ◽  
Electronic Band ◽  
Level Shifts ◽  
Direct Band ◽  
Near Term

ABSTRACTWide bandgap III-V nitrides, such as GaN and AlN, have become topical in the near-term technology of blue lasers. We report detailed electronic band-structure calculations for (AlN)m(GaN)n [001] zinc-blende superlattices (SL), with m + n ≤ 12, using the all-electron full-potential linear-muffin-tin-orbital method. For n ≥ 3, the SL are found to have a direct band gap. For n ≤ 2 and m ≥ 3, all the band gaps are indirect. In ultrathin SL, m ≤ 3 and n ≤ 2, only (m, n)= (3,1) is found to have an indirect gap. The band offsets are estimated by calculating the core-level shifts of nitrogen atoms in the central planes of the GaN and A1N layers. The calculated densities of states, electron- and hole- effective masses (m), etc., as a function of m and n, are reported; a remarkable dependence of m on the number of layers is revealed.

Helical Peptides Design for Molecular Dipoles Functionalization of Wide Band Gap Oxides

2020 ◽  
Vol 142 (7) ◽  
pp. 3489-3498 ◽  
Author(s):  
Yuan Chen ◽  
Jonathan Viereck ◽  
Ryan Harmer ◽  
Sylvie Rangan ◽  
Robert A. Bartynski ◽  
...  
Keyword(s):  
Band Gap ◽  
Wide Band ◽  
Wide Band Gap ◽  
Helical Peptides

scholarly journals UNFOLDING BAND AND ABSORPTION ENERGY SHIFT OF Si-Ge NANO CRYSTALS FROM FIRST-PRINCIPLES CALCULATIONS

2020 ◽  
Vol 31 ◽  
Author(s):  
Van Quang Tran
Keyword(s):  
Band Gap ◽  
Brillouin Zone ◽  
First Principles ◽  
Density Functional ◽  
Energy Shift ◽  
Valence Band Maximum ◽  
Band Structures ◽  
Electronic Band ◽  
Absorption Energy ◽  
Electronic Band Structures

Physical properties of the Si1-xGex alloys (x being the composition of Ge) can be understood and predicted from their electronic band structures. In this paper, electronic band structures of the Si1-xGex alloys are calculated using the first-principles density functional theory. The supper cell approach employed in our calculations leads to the folding of electronic bands into the smaller Brillouin zone of the supercell, especially at the Γ point. This often leads to the misinterpretation that the materials have direct band gap. The problem can be resolved by the band unfolding technique which allows one to recover the primitive cell picture of band structure of Si1-xGex. As a result, unfolded electronic bands correctly show an indirect band gap with the valence band maximum (VBM) at the Γ point and the conduction band minimum (CBM) shifted away from Γ. The CBM is gradually shifted from a point along ΓX path (associated with Si) to the L point (associated with Ge) with the increased Ge composition x and the switching occurs at x in the range of 0.6~0.8 which is in accordance with the calculation using kp method. Moreover, the additional electron pockets appear and develop at Γ and L. This provides more comprehensive understanding for our recent experimental observations on the shift of the absorption energy assigned to E1 direct transitions within L and Γ points in the Brillouin zone of Si1-xGex alloy nanocrystals.

TEM and cathodoluminescence of precipitates in II-VI semiconductors

1988 ◽  
Vol 46 ◽  
pp. 488-489
Author(s):  
Joanna L. Batstone
Keyword(s):  
Crystal Growth ◽  
Band Gap ◽  
Local Strain ◽  
Wide Band ◽  
Optoelectronic Device ◽  
Wide Band Gap ◽  
Bulk Crystal Growth ◽  
Transmission Electron ◽  
Device Applications ◽  
Stoichiometry Control

Interest in II-VI semiconductors centres around optoelectronic device applications. The wide band gap II-VI semiconductors such as ZnS, ZnSe and ZnTe have been used in lasers and electroluminescent displays yielding room temperature blue luminescence. The narrow gap II-VI semiconductors such as CdTe and HgxCd1-x Te are currently used for infrared detectors, where the band gap can be varied continuously by changing the alloy composition x.Two major sources of precipitation can be identified in II-VI materials; (i) dopant introduction leading to local variations in concentration and subsequent precipitation and (ii) Te precipitation in ZnTe, CdTe and HgCdTe due to native point defects which arise from problems associated with stoichiometry control during crystal growth. Precipitation is observed in both bulk crystal growth and epitaxial growth and is frequently associated with segregation and precipitation at dislocations and grain boundaries. Precipitation has been observed using transmission electron microscopy (TEM) which is sensitive to local strain fields around inclusions.

Wide Band-Gap Kesterite Thin Films for Photovoltaic Applications

2018 ◽  
Author(s):  
Raquel Caballero ◽  
Leonor de la Cueva ◽  
Andrea Ruiz-Perona ◽  
Yudenia Sánchez ◽  
Markus Neuschitzer ◽  
...  
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Wide Band ◽  
Wide Band Gap ◽  
Photovoltaic Applications

Preparation and Characterization of Polyvinylidene Fluoride/ZrO2-TiO2 Optical Film with Wide Band Gap and High Refractive Index

2013 ◽  
Vol 28 (6) ◽  
pp. 671-676 ◽  
Author(s):  
Yu-Qing ZHANG ◽  
Li-Li ZHAO ◽  
Shi-Long XU ◽  
Chao ZHANG ◽  
Xiao-Ying CHEN ◽  
...  
Keyword(s):  
Refractive Index ◽  
Band Gap ◽  
Polyvinylidene Fluoride ◽  
Wide Band ◽  
High Refractive Index ◽  
Wide Band Gap ◽  
Optical Film
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