scholarly journals Calculation for High Pressure Behaviour of Potential Solar Cell Materials Cu2FeSnS4 and Cu2MnSnS4

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 151
Author(s):  
Tim Küllmey ◽  
Miguel González ◽  
Eva M. Heppke ◽  
Beate Paulus
Keyword(s):  
High Pressure ◽  
Electronic Structure ◽  
Solar Cell ◽  
Structural Model ◽  
Structural Models ◽  
Type Structure ◽  
Lower Pressure ◽  
First Principle ◽  
Structure Changes ◽  
Magnetic Nature

Exploring alternatives to the Cu2ZnSnS4 kesterite solar cell absorber, we have calculated first principle enthalpies of different plausible structural models (kesterite, stannite, P4¯ and GeSb type) for Cu2FeSnS4 and Cu2MnSnS4 to identify low and high pressure phases. Due to the magnetic nature of Fe and Mn atoms we included a ferromagnetic (FM) and anti-ferromagnetic (AM) phase for each structural model. For Cu2FeSnS4 we predict the following transitions: P4¯ (AM) →16.3GPa GeSb type (AM) →23.0GPa GeSb type (FM). At the first transition the electronic structure changes from semi-conducting to metallic and remains metallic throughout the second transition. For Cu2MnSnS4, we predict a direct AM (kesterite) to FM (GeSb-type) transitions at somewhat lower pressure (12.1 GPa). The GeSb-type structure also shows metallic behaviour.

First-Principle of the Electronic Structure and Optical Property of LaBr3Under High Pressure

2013 ◽  
Vol 33 (2) ◽  
pp. 0216002
Author(s):  
冒晓莉 Mao Xiaoli ◽  
葛益娴 Ge Yixian ◽  
马涛 Ma Tao ◽  
张加宏 Zhang Jiahong
Keyword(s):  
High Pressure ◽  
Electronic Structure ◽  
Optical Property ◽  
First Principle

High-pressure studies of MgTe using first-principle electronic-structure calculations

1999 ◽  
Vol 60 (17) ◽  
pp. 11846-11847 ◽  
Author(s):  
Chhanda Basu Chaudhuri ◽  
G. Pari ◽  
Abhijit Mookerjee ◽  
A. K. Bhattacharyya
Keyword(s):  
High Pressure ◽  
Electronic Structure ◽  
Electronic Structure Calculations ◽  
First Principle ◽  
High Pressure Studies ◽  
Structure Calculations

Ab initio investigations of TlI-type compounds under high pressure

2004 ◽  
Vol 219 (6) ◽  
Author(s):  
Daniel Becker ◽  
Horst P. Beck
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Electron Pair ◽  
Elevated Pressure ◽  
Type Structure ◽  
Electronic Density ◽  
Structure Changes ◽  
Cscl Type ◽  
Wide Pressure Range ◽  
The Stability

AbstractIn this work, we present a theoretical study (based on DFT-calculations) in a wide pressure range of the structural and electronic properties and the stability of compounds crystallising in a TlI- or CrB-type structure. Both structure types have the characteristic structural feature of zigzag chains with unusual short homonuclear distances. The main focus of this study is to elucidate the nature of bonding within these zigzag chains at ambient and elevated pressure. For this purpose we discuss the evolution of the distances within the zigzag chains with pressure, the transition pressure of the phase transition to a CsCl-type arrangement (high-pressure phase) and compressibilities of the low- and high-pressure phases. For a better understanding of the structure and bonding, the band structures of these compounds are evaluated. The calculations are complemented by an orbital analysis using the crystal orbital Hamilton population (COHP) and an analysis of the electronic density topology with the electron localisation function (ELF). Our study indicates that there is a bonding electron pair in compounds crystallising in the CrB-type structure and that the nature of the electron pair does not change significantly at elevated pressure up to the phase transition. However, the “character” of the additional electron pair in the In-monohalides (TlI-type structure) changes with increasing pressure from nonbonding to bonding. The phase transition to a CsCl- type structure implies a fundamental change to nonbonding stereochemically inert electron pairs for all compounds.

ELECTRONIC AND MAGNETIC STRUCTURE OF THE HIGH PRESSURE PHASE OF Li2CuO2

2011 ◽  
Vol 25 (26) ◽  
pp. 3409-3414 ◽  
Author(s):  
ZHI LI ◽  
JOHN S. TSE ◽  
SHUJIE YOU ◽  
C. Q. JIN ◽  
TOSHIAKI IITAKA
Keyword(s):  
High Pressure ◽  
Electronic Structure ◽  
Finite Temperature ◽  
Monoclinic Phase ◽  
Magnetocrystalline Anisotropy ◽  
Antiferromagnetic Interaction ◽  
High Pressure Phase ◽  
First Principle ◽  
Antiferromagnetic State ◽  
Pressure Phase

The magnetic and electronic structure of monoclinic phase Li 2 CuO 2 under high pressure is studied by first principle with GGA+U calculations. It is shown that the C-type antiferromagnetic state of the ambient structure is maintained in the monoclinic high pressure phase. This is due to the preservation of the ferromagnetic CuO 2 chains in the structure. It is expected that the weak interchain antiferromagnetic interaction can easily disrupt by finite temperature, and the magnetocrystalline anisotropy in this insulator is extremely weak.

scholarly journals Vacancy ordering induced topological electronic transition in bulk Eu2ZnSb2

2021 ◽  
Vol 7 (6) ◽  
pp. eabd6162
Author(s):  
Honghao Yao ◽  
Chen Chen ◽  
Wenhua Xue ◽  
Fengxian Bai ◽  
Feng Cao ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Essential Role ◽  
Structural Models ◽  
Electronic Transitions ◽  
Cation Ordering ◽  
Microscopy Imaging ◽  
Structure Changes ◽  
Transmission Electron ◽  
Vacancy Ordering ◽  
Zn Vacancy

Metal-semiconductor transitions from changes in edge chirality from zigzag to armchair were observed in many nanoribbon materials, especially those based on honeycomb lattices. Here, this is generalized to bulk complex Zintl semiconductors, exemplified by Eu2ZnSb2 where the Zn vacancy ordering plays an essential role. Five Eu2ZnSb2 structural models are proposed to guide transmission electron microscopy imaging. Zigzag vacancy ordering models show clear metallicity, while the armchair models are semiconducting with indirect bandgaps that monotonously increase with the relative distances between neighboring ZnSb2 chains. Topological electronic structure changes based on cation ordering in a Zintl compound point toward tunable and possibly switchable topological behavior, since cations in these are often mobile. Thus, their orderings can often be adjusted by temperature, minor alloying, and other approaches. We explain the electronic structure of an interesting thermoelectric and point the way to previously unidentified types of topological electronic transitions in Zintl compounds.

First-principle study of electronic structure of montmorillonite at high pressure

2020 ◽  
Vol 34 (25) ◽  
pp. 2050263
Author(s):  
Zhi-Jie Fang ◽  
Kai-Yuan Gou ◽  
Man Mo ◽  
Ji-Shu Zeng ◽  
Hao He ◽  
...  
Keyword(s):  
High Pressure ◽  
Electronic Structure ◽  
Band Structure ◽  
Conduction Band ◽  
Stress Process ◽  
First Principle ◽  
Density Of State ◽  
Tunnel Engineering ◽  
Crystal Face ◽  
Different Levels

The first-principle method was used to study the electronic structure of montmorillonite under high pressure. The calculated results show that the Si–O bond is more stable than the Al–O bond as the pressure was increased, while the H–O bond is almost independent of this variable. More importantly, band structure of montmorillonite changes from indirect bandgap to direct bandgap and vice-versa at 33.2 GPa and 39.2 GPa, respectively. Furthermore, density of state split phenomenon appeared in conduction band region. By calculating the montmorillonite elasticity constants under different levels of stress, the results show that C33 and C66 perpendicular to the crystal face are greatly affected by the stress. Moreover, C44 with the minimum changes during the entire stress process. The calculated results will not only help to understand the electronic structure of montmorillonite under pressure, but also provide theoretical guidance for deal with the safe problems of tunnel engineering.

New Metal Nitride Compounds: Can they be Synthesized at High-Pressures?

2007 ◽  
Vol 1040 ◽  
Author(s):  
Peter Kroll
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Phase Diagrams ◽  
High Pressures ◽  
Type Structure ◽  
First Principle ◽  
Metal Nitride ◽  
Temperature Conditions ◽  
High Pressure High Temperature

AbstractWe apply our procedure of including nitrogen fugacity into thermochemical calculations to compute phase diagrams in the rhenium-nitrogen and ruthenium-nitrogen systems. The combination of first-principle and thermochemical calculations let us predict the sequential nitridation of Re at high-pressure/high-temperature conditions. At 3000 K, Re will react with nitrogen at about 32 GPa yielding ReN. Formation of ReN2 with CoSb2-type structure is predicted for pressures exceeding 50 GPa at this temperature. The recently proposed marcasite-type RuN2 will be attainable at 3000 K at pressures above 30 GPa from a mixture of Ru and RuN2.

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