First principles calculations of the band offset at SrTiO3−TiO2 interfaces

2012 ◽  
Vol 101 (14) ◽  
pp. 141606 ◽  
Author(s):  
Nunzio Roberto D'Amico ◽  
Giovanni Cantele ◽  
Domenico Ninno
Keyword(s):  
First Principles ◽  
Band Offset ◽  
First Principles Calculations

scholarly journals Probing embedded topological modes in bulk-like GeTe-Sb2Te3 heterostructures

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hisao Nakamura ◽  
Johannes Hofmann ◽  
Nobuki Inoue ◽  
Sebastian Koelling ◽  
Paul M. Koenraad ◽  
...  
Keyword(s):  
Topological Insulator ◽  
First Principles ◽  
Atom Probe ◽  
Photoemission Spectroscopy ◽  
Band Offset ◽  
First Principles Calculations ◽  
Vacuum Interface ◽  
Topological States ◽  
Experimental Findings ◽  
Thick Layers

AbstractThe interface between topological and normal insulators hosts metallic states that appear due to the change in band topology. While topological states at a surface, i.e., a topological insulator-air/vacuum interface, have been studied intensely, topological states at a solid-solid interface have been less explored. Here we combine experiment and theory to study such embedded topological states (ETSs) in heterostructures of GeTe (normal insulator) and $$\hbox {Sb}_2$$ Sb 2 $$\hbox {Te}_3$$ Te 3 (topological insulator). We analyse their dependence on the interface and their confinement characteristics. First, to characterise the heterostructures, we evaluate the GeTe-Sb$$_2$$ 2 Te$$_3$$ 3 band offset using X-ray photoemission spectroscopy, and chart the elemental composition using atom probe tomography. We then use first-principles to independently calculate the band offset and also parametrise the band structure within a four-band continuum model. Our analysis reveals, strikingly, that under realistic conditions, the interfacial topological modes are delocalised over many lattice spacings. In addition, the first-principles calculations indicate that the ETSs are relatively robust to disorder and this may have practical ramifications. Our study provides insights into how to manipulate topological modes in heterostructures and also provides a basis for recent experimental findings [Nguyen et al. Sci. Rep. 6, 27716 (2016)] where ETSs were seen to couple over thick layers.

scholarly journals First-principles calculations on CuInSe2/AlP heterostructures

2020 ◽  
Vol 8 (14) ◽  
pp. 4732-4742 ◽  
Author(s):  
Pingping Jiang ◽  
Marie-Christine Record ◽  
Pascal Boulet
Keyword(s):  
Conduction Band ◽  
Conversion Efficiency ◽  
First Principles ◽  
Band Offset ◽  
First Principles Calculations ◽  
Conduction Band Offset

Heterostructures based on a CuInSe2 absorber with an AlP buffer have a 12 meV conduction band offset and achieved 27.39% of conversion efficiency.

First principles calculations of the band offset of the ZnSe/BeTe heterojunctions

1998 ◽  
Vol 123-124 ◽  
pp. 445-448 ◽  
Author(s):  
P. Rodríguez-Hernández ◽  
M. González-Díaz ◽  
A. Mun˜oz
Keyword(s):  
First Principles ◽  
Band Offset ◽  
First Principles Calculations

Theoretical Studies of ZnO and Related MgxZn1-xO Alloy Band Structures

1998 ◽  
Vol 537 ◽  
Author(s):  
Walter R. L. Lambrecht ◽  
Sukit Limpijumnong ◽  
B. Segall
Keyword(s):  
Experimental Data ◽  
Band Gap ◽  
Valence Band ◽  
First Principles ◽  
Alloy System ◽  
Band Offset ◽  
Type I ◽  
Theoretical Studies ◽  
First Principles Calculations ◽  
Band Position

AbstractFirst principles calculations are carried out for ZnO, MgO and ZnMgO2 in various crystal structures. The nature of the valence band ordering in ZnO is shown to depend strongly on the Zn3d band position. MgO in the wurtzitic form is found to gave an unusual 5-fold coordiated structure. The band gap dependence in the alloy system is found to be in fair agreement with experimental data and the band-offset is predicted to be type I.

scholarly journals Theoretical Studies of ZnO and Related MgxZn1−xO Alloy Band Structures

1999 ◽  
Vol 4 (S1) ◽  
pp. 582-587 ◽  
Author(s):  
Walter R. L. Lambrecht ◽  
Sukit Limpijumnong ◽  
B. Segall
Keyword(s):  
Experimental Data ◽  
Band Gap ◽  
Valence Band ◽  
First Principles ◽  
Alloy System ◽  
Band Offset ◽  
Type I ◽  
Theoretical Studies ◽  
First Principles Calculations ◽  
Band Position

First principles calculations are carried out for ZnO, MgO and ZnMgO2 in various crystal structures. The nature of the valence band ordering in ZnO is shown to depend strongly on the Zn3d band position. MgO in the wurtzitic form is found to gave an unusual 5-fold coordiated structure. The band gap dependence in the alloy system is found to be in fair agreement with experimental data and the band-offset is predicted to be type I.

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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