scholarly journals Al Doped ZnO Thermoelectrics Determined from Electronic Structure

2020 ◽  
Author(s):  
Rundong Wan ◽  
Quanwei Jiang ◽  
Zhengfu Zhang ◽  
Sharon Kao-Walter ◽  
Ying Lei ◽  
...  

Abstract For the aluminium doped wurtzite ZnO, comparing the Boltzmann transport theory calculated results and existing experiments, we acquire a few properties that are inaccessible otherwise. We find that the doping makes the samples metallic as the shifted Fermi levels are above the conduction band edge. We further find that the contradictory conclusions from two experiments with similar formula can be attributed to the quite disparate carrier concentrations and carrier mobility and the carrier mobility strong relates to the sample preparation.

2019 ◽  
Vol 7 (25) ◽  
pp. 7664-7671 ◽  
Author(s):  
Enamullah Enamullah ◽  
Pil-Ryung Cha

In the combined framework of density functional and Boltzmann transport theory, we have systematically studied the electronic structure, mechanical stability and thermoelectric properties of the semiconducting quaternary Heusler alloy, CoFeTiAl.


2018 ◽  
Vol 5 (3) ◽  
pp. 171827 ◽  
Author(s):  
Daifeng Zou ◽  
Chuanbin Yu ◽  
Yuhao Li ◽  
Yun Ou ◽  
Yongyi Gao

The electronic structures of monolayer and bilayer SnSe 2 under pressure were investigated by using first-principles calculations including van der Waals interactions. For monolayer SnSe 2 , the variation of electronic structure under pressure is controlled by pressure-dependent lattice parameters. For bilayer SnSe 2 , the changes in electronic structure under pressure are dominated by intralayer and interlayer atomic interactions. The n -type thermoelectric properties of monolayer and bilayer SnSe 2 under pressure were calculated on the basis of the semi-classical Boltzmann transport theory. It was found that the electrical conductivity of monolayer and bilayer SnSe 2 can be enhanced under pressure, and such dependence can be attributed to the pressure-induced changes of the Se–Sn antibonding states in conduction band. Finally, the doping dependence of power factors of n -type monolayer and bilayer SnSe 2 at three different pressures were estimated, and the results unveiled that thermoelectric performance of n -type monolayer and bilayer SnSe 2 can be improved by applying external pressure. This study benefits to understand the nature of the transport properties for monolayer and bilayer SnSe 2 under pressure, and it offers valuable insight for designing high-performance thermoelectric few-layered SnSe 2 through strain engineering induced by external pressure.


1997 ◽  
Vol 493 ◽  
Author(s):  
J Robertson ◽  
C W Chen

ABSTRACTThe electronic structure of SrBi2Ta2O9 and related oxides such as SrBi2Nb2O9, Bi2WO6 and Bi3Ti4O12 have been calculated by the tight-binding method. In each case, the band gap is about 4.1 eV and the band edge states occur on the Bi-O layers and consist of mixed O p/Bi s states at the top of the valence band and Bi p states at the bottom of the conduction band. The main difference between the compounds is that Nb 5d and Ti 4d states in the Nb and Ti compounds lie lower than the Ta 6d states in the conduction band. The surface pinning levels are found to pin Schottky barriers 0.8 eV below the conduction band edge.


2017 ◽  
Vol 31 (29) ◽  
pp. 1750265 ◽  
Author(s):  
Guangtao Wang ◽  
Dongyang Wang ◽  
Xianbiao Shi ◽  
Yufeng Peng

We studied the crystal and electronic structures of LaOBiSSe and LaOBiSeS using first-principles calculations and confirmed that the LaOBiSSe (S atoms on the top of BiCh2 layer and Se atoms in the inner of it) is the stable structure. Then we calculate the thermoelectric properties of LaOBiSSe using the standard Boltzmann transport theory. The in-plane thermoelectric performance are better than that along the c-axis in this n-type material. The in-plane power factor [Formula: see text] of n-type LaOBiSSe is as high as 12 [Formula: see text]W/cmK2 at 900 K with figure of merit ZT = 0.53 and [Formula: see text]. The ZT maximum appears around [Formula: see text] in a wide temperature region. The results indicate that LaOBiSSe is a 2D material with good thermal performance in n-type doping.


RSC Advances ◽  
2020 ◽  
Vol 10 (48) ◽  
pp. 28501-28508
Author(s):  
Yang Hu ◽  
Yurong Jin ◽  
Guangbiao Zhang ◽  
Yuli Yan

We investigate the transport properties of bulk Ca2YZ (Y = Au, Hg; Z = As, Sb, Bi, Sn and Pb) by a combination method of first-principles and Boltzmann transport theory.


2019 ◽  
Vol 21 (2) ◽  
pp. 851-858 ◽  
Author(s):  
Xiuxian Yang ◽  
Zhenhong Dai ◽  
Yinchang Zhao ◽  
Wenchao Niu ◽  
Jianye Liu ◽  
...  

We have used first principle calculations together with Boltzmann transport theory to calculate the electronic structure and thermoelectric properties of CoSb3 and IrSb3.


2013 ◽  
Vol 06 (05) ◽  
pp. 1340013 ◽  
Author(s):  
DAVID J. SINGH ◽  
DAVID PARKER

We report calculations of the doping and temperature dependent thermopower of Ru 2 Si 3 based on Boltzmann transport theory and the first principles electronic structure. We find that the performance reported to date can be significantly improved by optimization of the doping level and that ultimately n-type should have higher ZT than p-type.


1997 ◽  
Vol 107 (16) ◽  
pp. 6023-6031 ◽  
Author(s):  
James V. Coe ◽  
Alan D. Earhart ◽  
Michael H. Cohen ◽  
Gerald J. Hoffman ◽  
Harry W. Sarkas ◽  
...  

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