Prediction of New Fingerprints of Ordering in GaInP2 Alloys

1995 ◽  
Vol 417 ◽  
Author(s):  
Alberto Franceschetti ◽  
Su-Huai Wei ◽  
Alex Zunger
Keyword(s):  
Band Gap ◽  
Effective Mass ◽  
Pressure Coefficient ◽  
Strong Anisotropy ◽  
Electron Effective Mass ◽  
Effective Masses ◽  
Epitaxial Strain ◽  
Degree Of Order ◽  
Good Agreement ◽  
Disordered Alloy

AbstractUsing ab initio all-electron methods, we investigate the evolution of effective masses, deformation potentials and pressure coefficients with the degree of long-range order in spontaneously ordered Ga0.5In0.5P alloys. We find that (i) the electron effective mass in the ordering direction increases significantly with the degree of order, while the effective mass in the perpendicular direction decreases; this produces a strong anisotropy of the electron effective mass which is not present in the disordered alloy; (ii) the band-gap deformation potential for (001) epitaxial strain decreases with increasing degree of order, reflecting the extent of the ordering-induced Γ - L coupling; (iii) the band-gap pressure coefficient decreases from 8.4 meV/kbar in the disordered alloy to 6.6 meV/kbar in the ordered CuPt structure; interpolation to partial degrees of order leads to good agreement with recent high-pressure experiments.

scholarly journals Band gap and work function tailoring of SnO2 for improved transparent conducting ability in photovoltaics

2016 ◽  
Vol 4 (7) ◽  
pp. 1467-1475 ◽  
Author(s):  
Alex M. Ganose ◽  
David O. Scanlon
Keyword(s):  
Work Function ◽  
Band Gap ◽  
Effective Mass ◽  
Electron Affinity ◽  
Transparent Conducting Oxide ◽  
Optical Transparency ◽  
Electron Effective Mass ◽  
Transparent Conducting ◽  
Photovoltaic Applications

Alloying of PbO2 with SnO2 results in a material with a tuneable band gap, larger electron affinity and smaller electron effective mass, whilst maintaining high levels of optical transparency. These properties are expected to give rise to a more efficient transparent conducting oxide for use in photovoltaic applications.

Electron effective-mass values in GaxIn1−xSb alloys

1969 ◽  
Vol 47 (6) ◽  
pp. 631-636 ◽  
Author(s):  
Marcel J. Aubin ◽  
Mathew B. Thomas ◽  
Eric H. van Tongerloo ◽  
John C. Woolley
Keyword(s):  
Effective Mass ◽  
High Frequency ◽  
Room Temperature ◽  
Composition Range ◽  
Bridgman Technique ◽  
Scattering Parameter ◽  
Electron Effective Mass ◽  
High Frequency Dielectric Constant ◽  
The Matrix ◽  
Good Agreement

Room-temperature measurements of Faraday rotation, magneto–thermoelectric power, and infrared reflectance have been made on homogeneous coarsely polycrystalline n-type samples of GaxIn1−xSb alloys produced by the horizontal Bridgman technique. Using these data and a Kane equation for the (000) conduction band, values of the bottom of the band effective mass m00* have been determined over the composition range 0 < x < 0.85, i.e. the range in which the subsidiary [Formula: see text] minima make no contribution. The results from the three different techniques show very good agreement. From the data, values are obtained also for the square of the matrix element P2, the high-frequency dielectric constant ε∞, and the scattering parameter s for the various alloy specimens.

Band-gap energy and electron effective mass of polycrystalline Zn3N2

2006 ◽  
Vol 99 (7) ◽  
pp. 076101 ◽  
Author(s):  
Toshikazu Suda ◽  
Kazuhiko Kakishita
Keyword(s):  
Band Gap ◽  
Effective Mass ◽  
Band Gap Energy ◽  
Electron Effective Mass ◽  
Gap Energy

scholarly journals AB INITIO STUDY OF SIZE AND STRAIN EFFECTS ON THE ELECTRONIC PROPERTIES OF Si NANOWIRES

2009 ◽  
Vol 01 (03) ◽  
pp. 483-499 ◽  
Author(s):  
X.-H. PENG ◽  
A. ALIZADEH ◽  
S. K. KUMAR ◽  
S. K. NAYAK
Keyword(s):  
Band Gap ◽  
Electronic Properties ◽  
Effective Mass ◽  
Density Functional ◽  
Compressive Strain ◽  
Si Nanowires ◽  
Functional Theory ◽  
Strain Effects ◽  
Size Dependent ◽  
Effective Masses

We have applied density-functional theory (DFT) based calculations to investigate the size and strain effects on the electronic properties, such as band structures, energy gaps and effective masses of the electron and the hole, in Si nanowires along the 〈110〉 direction with diameters up to 5 nm. Under uniaxial strain, we find that the band gap varies with strain and this variation is size dependent. For the 1–2 nm wire, the band gap is a linear function of strain, while for the 2–4 nm wire the gap variation with strain shows nearly parabolic behaviour. This size dependence of the gap variation with strain is explained on the basis of orbital characters of the band edges. In addition we find that the expansive strain increases the effective mass of the hole, while compressive strain increases the effective mass of the electron. The study of size and strain effects on effective masses shows that effective masses of the electron and the hole can be reduced by tuning the diameter of the wire and applying appropriate strain.

Theory of the Quasiparticle Effective Masses in Semiconductors based on an Electron Self Energy Approach

1990 ◽  
Vol 193 ◽  
Author(s):  
Xuejun Zhu ◽  
Mark S. Hybertsen ◽  
Steven G. Louie
Keyword(s):  
Effective Mass ◽  
Local Density ◽  
Energy Operator ◽  
Electron Interaction ◽  
Electron Effective Mass ◽  
Self Energy ◽  
Effective Masses ◽  
The Matrix ◽  
Energy Renormalization ◽  
Energy Dependent

ABSTRACTA conceptually complete formalism for the quasiparticle effective masses in semiconductors is proposed. Our approach is based. on a generalized form of the theory, including the effects of the nonlocal, energy dependent electron self: energy operator Σ, which accounts for the electron-electron interaction. This introduces two -important effects on the expression of the effective mass: an explicit energy renormalization and an extra contribution to the matrix element that enters the usual . Our preliminary numerical results for prototypical GaAs show promising improvements over the results from the local density approximation for the calculated electron effective mass compared to experimental data.

Effective masses in a dense fermion background — Applied to neutrinos, dark matter and dark energy

2014 ◽  
Vol 29 (21) ◽  
pp. 1444010
Author(s):  
Bruce H. J. McKellar ◽  
T. J. Goldman ◽  
G. J. Stephenson
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Scalar Field ◽  
Effective Mass ◽  
Negative Pressure ◽  
Expectation Value ◽  
Effective Masses ◽  
Neutrino Astrophysics

If fermions interact with a scalar field, and there are many fermions present the scalar field may develop an expectation value and generate an effective mass for the fermions. This can lead to the formation of fermion clusters, which could be relevant for neutrino astrophysics and for dark matter astrophysics. Because this system may exhibit negative pressure, it also leads to a model of dark energy.

Photoconductivité dans l'alliage GaAsxSb1−x en présence d'un champ magnétique

1974 ◽  
Vol 52 (8) ◽  
pp. 743-747 ◽  
Author(s):  
A. Filion ◽  
E. Fortin
Keyword(s):  
Magnetic Fields ◽  
Band Gap ◽  
Effective Mass ◽  
Alloy Composition ◽  
Longitudinal Optical ◽  
Optical Phonons ◽  
Champ Magnétique

The intrinsic photoconductivity of several samples of the alloy GaAsxSb1−x has been studied at 4.2 K in the presence of magnetic fields of up to 65 kG. Values for the band-gap, the reduced effective mass of the carriers, the energy of the longitudinal optical phonons across the alloy composition are deduced from the measurements.

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