Overlayer resonance and quantum well state ofCs∕Cu(111)studied with angle-resolved photoemission, LEED, and first-principles calculations

2007 ◽  
Vol 75 (15) ◽  
Author(s):  
M. Breitholtz ◽  
V. Chis ◽  
B. Hellsing ◽  
S.-Å. Lindgren ◽  
L. Walldén
Keyword(s):  
Quantum Well ◽  
First Principles ◽  
First Principles Calculations ◽  
Quantum Well State

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 Efficiency limits of Si/SiO2 quantum well solar cells from first-principles calculations

2009 ◽  
Vol 105 (10) ◽  
pp. 104511 ◽  
Author(s):  
Thomas Kirchartz ◽  
Kaori Seino ◽  
Jan-Martin Wagner ◽  
Uwe Rau ◽  
Friedhelm Bechstedt
Keyword(s):  
Solar Cells ◽  
Quantum Well ◽  
First Principles ◽  
First Principles Calculations

Electronic Structure and X-ray Absorption Spectra of Rutile TiO2 Using First-Principles Calculations

2014 ◽  
Vol 52 (12) ◽  
pp. 1025-1029
Author(s):  
Min-Wook Oh ◽  
Tae-Gu Kang ◽  
Byungki Ryu ◽  
Ji Eun Lee ◽  
Sung-Jae Joo ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Absorption Spectra ◽  
First Principles ◽  
First Principles Calculations ◽  
Rutile Tio2 ◽  
X Ray ◽  
X Ray Absorption

To Bend or Not to Bend, the Dilemma of Multiple Bonds

2019 ◽  
Author(s):  
Michele Pizzocchero ◽  
Matteo Bonfanti ◽  
Rocco Martinazzo
Keyword(s):  
First Principles ◽  
2D Materials ◽  
Main Group ◽  
First Principles Calculations ◽  
Group 14 ◽  
Multiple Bonds ◽  
Main Group Elements ◽  
Structural Distortions

The manuscript addresses the issue of the structural distortions occurring at multiple bonds between high main group elements, focusing on group 14. These distortions are known as trans-bending in silenes, disilenes and higher group analogues, and buckling in 2D materials likes silicene and germanene. A simple but correlated \sigma + \pi model is developed and validated with first-principles calculations, and used to explain the different behaviour of second- and higher- row elements.

Thermodynamic Stability of Hexagonal and Rhombohedral Bn at Cvd Conditions from Van der Waals Corrected First Principles Calculations

2019 ◽  
Author(s):  
Henrik Pedersen ◽  
Björn Alling ◽  
Hans Högberg ◽  
Annop Ektarawong
Keyword(s):  
Thin Films ◽  
Thermodynamic Stability ◽  
First Principles ◽  
Thermal Equilibrium ◽  
Density Functional ◽  
Van Der Waals ◽  
Chemical Vapor ◽  
First Principles Calculations ◽  
Functional Theory ◽  
The Stability

Thin films of boron nitride (BN), particularly the sp<sup>2</sup>-hybridized polytypes hexagonal BN (h-BN) and rhombohedral BN (r-BN) are interesting for several electronic applications given band gaps in the UV. They are typically deposited close to thermal equilibrium by chemical vapor deposition (CVD) at temperatures and pressures in the regions 1400-1800 K and 1000-10000 Pa, respectively. In this letter, we use van der Waals corrected density functional theory and thermodynamic stability calculations to determine the stability of r-BN and compare it to that of h-BN as well as to cubic BN and wurtzitic BN. We find that r-BN is the stable sp<sup>2</sup>-hybridized phase at CVD conditions, while h-BN is metastable. Thus, our calculations suggest that thin films of h-BN must be deposited far from thermal equilibrium.

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