Engineering electronic band structure and thermoelectric performance of GeTe via lattice structure manipulation from first-principles

Author(s):  
Tianyu Wang ◽  
Chun Zhang ◽  
Jia-Yue Yang ◽  
Linhua Liu

GeTe has become a high-performance thermoelectric material with a figure of merit (ZT) over two through alloying and band engineering strategies. Yet, the question on how to effective engineer electronic...

2019 ◽  
Vol 7 (3) ◽  
pp. 1045-1054 ◽  
Author(s):  
Hasbuna Kamila ◽  
Prashant Sahu ◽  
Aryan Sankhla ◽  
Mohammad Yasseri ◽  
Hoang-Ngan Pham ◽  
...  

Figure of merit zT mapping of p-Mg2Si1−xSnx with respect to carrier concentration.


Author(s):  
Supratik Mukherjee ◽  
Aiswarya T ◽  
Subrata Mondal ◽  
Ganapathy Vaitheeswaran

Abstract This article thoroughly addresses the structural, mechanical, vibrational, electronic band structure and the optical properties of the unexplored thallous perchlorate and perbromate from ab-initio calculations. The zone centered vibrational phonon frequencies shows, there is a blue shift in the mid and high frequency range from Cl → Br due to change in mass and force constant with respect to oxygen atom. From the band structure it is clear that the top of the valence band is due to thallium s states, whereas the bottom of the conduction band is due to halogen s and oxygen p states, showing similar magnitude of dispersion and exhibits a charge transfer character. These characteristics and the band gap obtained are consistent with that of a favourable scintillators. Our findings deliver directions for the design of efficient TlXO4 based scintillators with high performance which are desirable for distinct applications such as medical imaging, high energy physics experiments, nuclear security.


Author(s):  
Tai Ma ◽  
Jia Wang ◽  
Xu Li ◽  
Min Pu

Two-dimensional (2D) materials with robust ferromagnetism properties have high potentials for application in the field of spintronics. However, extensively pursued 2D sheets, including pure graphene, monolayer BN, and layered transition metal dichalcogenides, are either nonmagnetic or weakly magnetic. The elastic, electronic and magnetic properties of monolayer CrN are calculated using the plane wave pseudo potential method based on first-principles density function theory. Upon determining through calculation that the structure of the monolayer CrN nanosheet is stable, its layer modulus [Formula: see text] shows that its strain resistance is stronger than that of graphene. Through strain analysis, materials with a monolayer CrN type of structure can be obtained. It is determined that 10% of the change in equilibrium area is still applicable to the 2D EOS, showing that this structure is quite stable. The spin-polarized electronic band structure is also calculated under different plane symmetry strains. The plane strain can be used to effectively adjust the metallic and magnetic properties of the material. Analyses of the band structure and density of states reveal that this material is half-metallic, where the origin of the ferromagnetism is related to [Formula: see text]–[Formula: see text] exchange interactions between the Cr and N atoms. Monolayer CrN has semimetallic properties and strong ferromagnetic (FM) properties. The FM effect can enhance the stability of the material. The results show that monolayer CrN is a semimetallic material with good elastic properties and a strong FM property. This material is therefore expected to have good application rospects in the field of spin electronics.


2009 ◽  
Vol 23 (32) ◽  
pp. 5929-5934 ◽  
Author(s):  
T. JEONG

The electronic band structure of LuPd 2 Si 2 was studied based on the density functional theory within local density approximation and fully relativistic schemes. The Lu 4f states are completely filled and have flat bands around -5.0 eV. The fully relativistic band structure scheme shows that spin–orbit coupling splits the 4f states into two manifolds, the 4f7/2 and the 4f5/2 multiplet.


2017 ◽  
Vol 5 (5) ◽  
pp. 2235-2242 ◽  
Author(s):  
Min Ho Lee ◽  
Do-Gyun Byeon ◽  
Jong-Soo Rhyee ◽  
Byungki Ryu

We investigated the thermoelectric properties and electronic band structure calculation of Sn1−xAgxTe and Sn1.03−xAgxTe (x = 1, 3, 5, 7 mol%) compounds.


2009 ◽  
Vol 113 (19) ◽  
pp. 8460-8464 ◽  
Author(s):  
Luyan Li ◽  
Weihua Wang ◽  
Hui Liu ◽  
Xindian Liu ◽  
Qinggong Song ◽  
...  

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