Strain Effects on Optical Gain Properties of GaN/AlGaN Quantum Well Lasers

1996 ◽  
Vol 421 ◽  
Author(s):  
M. Suzuki ◽  
T. Uenoyama
Keyword(s):  
Quantum Well ◽  
First Principles ◽  
Carrier Density ◽  
Optical Gain ◽  
Uniaxial Strain ◽  
Quantum Well Lasers ◽  
Physical Parameters ◽  
First Principles Calculations ◽  
Strain Effects ◽  
Laser Performance

AbstractSubband structures and optical gains of the strained wurtzite GaN/AlGaN quantum well lasers are theoretically investigated on the basis of k.p theory. First-principles calculations are used for deriving the unknown physical parameters, such as deformation potentials. Neither compressive nor tensile biaxial strains are so effective on the reduction of the threshold carrier density. It is also found that the uniaxial strain in the c-plane is one of the preferable approaches for the efficient improvement of the laser performance.

scholarly journals Polarization effects on the interfacial conductivity in LaAlO3/SrTiO3heterostructures: a first-principles study

2016 ◽  
Vol 18 (9) ◽  
pp. 6831-6838 ◽  
Author(s):  
Maziar Behtash ◽  
Safdar Nazir ◽  
Yaqin Wang ◽  
Kesong Yang
Keyword(s):  
First Principles ◽  
Carrier Density ◽  
Uniaxial Strain ◽  
First Principles Calculations ◽  
Electron Carrier ◽  
Polarization Effects ◽  
First Principles Study

First-principles calculations predict the normalized electron carrier density (μ/μ0), the mobility (m*/m0), and the conductivity (σ/σ0) in LaAlO3/SrTiO3as a function of uniaxial strain.

Analysis of Wurtzite GaN/AlGaN Quantum Well Lasers from First-Principles Calculations

1995 ◽  
Vol 395 ◽  
Author(s):  
T. Uenoyama ◽  
M. Suzuki
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
First Principles ◽  
Optical Gain ◽  
Quantum Well Lasers ◽  
First Principles Calculation ◽  
Spin Orbit ◽  
Orbit Splitting ◽  
Large Hole ◽  
Spin Orbit Splitting

ABSTRACTOptical gain of wurtzite GaN/AlGaN quantum wells has been studied from a first-principles calculation using the k • p method. Most of the parameters in the k • p method were determined by fitting the band structures by the first-principles calculation. Owing to the small spin-orbit splitting energies of the wurtzite GaN and AIN, the optical gain has been calculated using the 6×6 Hamiltonian for the valence band. It is found that the large hole effective masses and the small spin-orbit splitting cause the higher threshold current density of wurtzite GaN/AlGaN quantum well lasers.

scholarly journals First-Principles Calculations of High-Pressure Physical Properties of Ti0.5Ta0.5 Alloy

Symmetry ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 796
Author(s):  
Fang Yu ◽  
Yu Liu
Keyword(s):  
High Pressure ◽  
Physical Properties ◽  
First Principles ◽  
Theoretical Study ◽  
Applied Pressure ◽  
Lattice Parameter ◽  
Physical Parameters ◽  
First Principles Calculations ◽  
Analysis Method ◽  
Metallic Bond

In this paper, an in-depth theoretical study on some physical properties of Ti0.5Ta0.5 alloy with systematic symmetry under high pressure is conducted via first-principles calculations, and relevant physical parameters are calculated. The results demonstrate that the calculated parameters, including lattice parameter, elastic constants, and elastic moduli, fit well with available theoretical and experimental data when the Ti0.5Ta0.5 alloy is under T = 0 and P = 0 , indicating that the theoretical analysis method can effectively predict the physical properties of the Ti0.5Ta0.5 alloy. The microstructure and macroscopic physical properties of the alloy cannot be destroyed as the applied pressure ranges from 0 to 50GPa, but the phase transition of crystal structure may occur in the Ti0.5Ta0.5 alloy if the applied pressure continues to increase according to the TDOS curves and charge density diagram. The value of Young’s and shear modulus is maximized at P = 25   GPa . The anisotropy factors A ( 100 ) [ 001 ] and A ( 110 ) [ 001 ] are equal to 1, suggesting the Ti0.5Ta0.5 alloy is an isotropic material at 28 GPa, and the metallic bond is strengthened under high pressure. The present results provide helpful insights into the physical properties of Ti0.5Ta0.5 alloy.

Optical gain of strained GaAsSb/GaAs quantum-well lasers: A self-consistent approach

2000 ◽  
Vol 88 (10) ◽  
pp. 5554-5561 ◽  
Author(s):  
Guobin Liu ◽  
Shun-Lien Chuang ◽  
Seoung-Hwan Park
Keyword(s):  
Quantum Well ◽  
Optical Gain ◽  
Quantum Well Lasers ◽  
Self Consistent ◽  
Consistent Approach
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