Electronic and Optical Properties of a-Si:H Films Alloyed with Sulfur

1994 ◽  
Vol 336 ◽  
Author(s):  
S.L. Wang ◽  
Z.H. Lin ◽  
J.M. Viner ◽  
P.C. Taylor
Keyword(s):  
Optical Properties ◽  
Fermi Level ◽  
Activation Energies ◽  
Significant Enhancement ◽  
Sulfur Concentration ◽  
Electronic And Optical Properties ◽  
Staebler Wronski Effect ◽  
Optically Induced

ABSTRACTAlloying a-Si:H with small amounts of sulfur (≤ 4 × 1020 cm−3) results in a significant enhancement in the photoconductivity and a suppression of the optically-induced degradation of the photoconductivity (Staebler-Wronski effect). The Magnitudes of the activation energies for conductivity imply that these films remain essentially intrinsic in nature. When the sulfur concentration is increased to about 2 to 3 at. %, the Fermi level rises by about 0.25 eV, a fact that suggests that sulfur may act as a very inefficient dopant in a-Si:H.

scholarly journals Structural, Electronic and Optical Properties of Stanene Doped Beryllium: A First Principle Study

2021 ◽  
pp. 32-40
Author(s):  
L. S. Taura ◽  
Isah Abdulmalik ◽  
A. S. Gidado ◽  
Abdullahi Lawal
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Fermi Level ◽  
Band Gap ◽  
Density Functional ◽  
Earth Metal ◽  
Dirac Cone ◽  
Electronic Band ◽  
Electronic And Optical Properties ◽  
Optical Applications

Stanene is a 2D hexagonal layer of tin with exceptional electronic and optical properties. However, the semiconductor applications of stanene are limited due to its zero band-gap. However, doping stanene could lead to a band gap opening, which could be a promising material for electronic and optical applications. In this work, optimized structure, electronic band structure, real and imaginary parts of the frequency-dependent dielectric function, electron loss function, and refractive index of stanene substitutionally doped with alkaline earth metal (beryllium) were analyzed using density functional theory (DFT) calculations as implemented in the quantum espresso and yambo suites. A pure stanene has a zero band gap energy, but with the inclusion of spin-orbit coupling in the electronic calculation of pure stanene, the band-gap is observed to open up by 0.1eV. Doping stanene with beryllium opens the band-gap and shifts the Dirac cone from the Fermi level, the band gap opens by 0.25eV, 0.55eV, and 0.8eV when the concentration of Beryllium is 12.5%, 25%, and 37.5% respectively. The Dirac cone vanished when the concentration of the dopant was increased to 50%.  The Fermi level is shifted towards the valence band edge indicating a p-type material. The material absorption shows that SnBe absorption ranges in the visible to the ultraviolet region, The refractive index in stanene doped beryllium (SnBe) was found to be higher than that of pristine stanene, the highest refractive index was 9.2 at SnBe25%. In a nutshell, the results indicate that stanene can be a good material for electronic and optical applications if doped with beryllium.

Electronic and Optical Properties of Sn-Doped Zno with and without O Vacancy

2014 ◽  
Vol 576 ◽  
pp. 9-13
Author(s):  
Xiao Chun Lai ◽  
Yi Bin Hou ◽  
Zhen Hui Sun ◽  
Lan Li Chen
Keyword(s):  
Optical Properties ◽  
Fermi Level ◽  
First Principles ◽  
Electron Transition ◽  
Low Energy ◽  
Optical Absorption Edge ◽  
Electronic And Optical Properties ◽  
Sn Doping ◽  
Doped Zno ◽  
O Vacancy

A systematic study on electronic and optical properties of Sn-doped ZnO with and without O vacancy has been performed using first-principles method. Our results revealed that the band gap of Sn-doped ZnO without O vacancy become narrow, demonstrating as red-shift and the electrons near the Fermi level originates from the delocalized Sn-5s. However, as O vacancy is introduced, Sn-5p states locate near the Fermi level. Furthermore, it is found that the optical absorption edge has been obviously changed after Sn doping in ZnO with and without O vacancy. Interestingly, in the low energy region, one new peak is observed for Sn-doped ZnO with O vacancy, due to the electron transition between Sn-5p and O-2p. The calculated results identify that O vacancy can improve the absorption of the visible light in Sn-doped ZnO.

ELECTRONIC AND OPTICAL PROPERTIES OF QUASIPERIODIC FIBONACCI SUPERLATTICES

1987 ◽  
Vol 48 (C5) ◽  
pp. C5-529-C5-532 ◽  
Author(s):  
F. LARUELLE ◽  
V. THIERRY-MIEG ◽  
M. C. JONCOUR ◽  
B. ETIENNE
Keyword(s):  
Optical Properties ◽  
Electronic And Optical Properties

First principles calculation of structural, electronic and optical properties of (001) and (110) growth axis (InN)/(GaN)n superlattices

2021 ◽  
Vol 67 (1 Jan-Feb) ◽  
pp. 7
Author(s):  
B. Bachir Bouiadjra ◽  
N. Mehnane ◽  
N. Oukli
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Scale Up ◽  
Energy Scale ◽  
First Principles Calculation ◽  
Full Potential ◽  
Electronic Band ◽  
Electronic And Optical Properties ◽  
Growth Axis

Based on the full potential linear muffin-tin orbitals (FPLMTO) calculation within density functional theory, we systematically investigate the electronic and optical properties of (100) and (110)-oriented (InN)/(GaN)n zinc-blende superlattice with one InN monolayer and with different numbers of GaN monolayers. Specifically, the electronic band structure calculations and their related features, like the absorption coefficient and refractive index of these systems are computed over a wide photon energy scale up to 20 eV. The effect of periodicity layer numbers n on the band gaps and the optical activity of (InN)/(GaN)n SLs in the both  growth axis (001) and (110) are examined and compared. Because of prospective optical aspects of (InN)/(GaN)n such as light-emitting applications, this theoretical study can help the experimental measurements.

Sign in / Sign up

Export Citation Format

Share Document