Significant Improvement in Electrical Conductivity and Figure of Merit of Nanoarchitectured Porous SrTiO3 by La Doping Optimization

Al Jumlat Ahmed; Md Shahriar A Hossain; Sheik Md Kazi Nazrul Islam; Frank Yun; Guangsai Yang; Ridwone Hossain; Aslam Khan; Jongbeom Na; Miharu Eguchi; Yusuke Yamauchi; Xiaolin Wang

doi:10.1021/acsami.0c01869

Significant Improvement in Electrical Conductivity and Figure of Merit of Nanoarchitectured Porous SrTiO₃ by La Doping Optimization

ACS Appl Mater Interfaces. 2020 Jun 24;12(25):28057-28064. doi: 10.1021/acsami.0c01869. Epub 2020 Jun 9.

Authors

Al Jumlat Ahmed¹, Md Shahriar A Hossain^{1

2

3}, Sheik Md Kazi Nazrul Islam^{1

4}, Frank Yun¹, Guangsai Yang¹, Ridwone Hossain¹, Aslam Khan⁵, Jongbeom Na^{2

6}, Miharu Eguchi^{2

6}, Yusuke Yamauchi^{2

7

6

8}, Xiaolin Wang¹

Affiliations

¹ Institute for Superconducting and Electronic Materials (ISEM), Australian Institute of Innovative Materials (AIIM), University of Wollongong, North Wollongong, New South Wales 2500, Australia.
² Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, Queensland 4072, Australia.
³ School of Mechanical and Mining Engineering, Faculty of Engineering, Architecture and Information Technology (EAIT), University of Queensland, Saint Lucia, Queensland 4072, Australia.
⁴ School of Mechanical and Physical Sciences, University of Technology Sydney, Sydney, New South Wales 2007, Australia.
⁵ King Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11451, Saudi Arabia.
⁶ Research Center for Functional Materials and International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
⁷ School of Chemical Engineering, Faculty of Engineering, Architecture and Information Technology (EAIT), University of Queensland, Saint Lucia, Queensland 4072, Australia.
⁸ Department of Plant & Environmental New Resources, Kyung Hee University, 1732 Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 446-701, Republic of Korea.

PMID: 32427455
DOI: 10.1021/acsami.0c01869

Abstract

SrTiO₃ is a well-studied n-type metal oxide based thermoelectric (TE) material. In this work, the first-principles calculation of La-doped SrTiO₃ has been performed using the density functional theory. In addition, high TE properties of bulk SrTiO₃ material have been achieved by introducing nanoscale porosity and optimizing carrier concentration by La doping. The X-ray diffraction, atomic resolution scanning transmission electron microscopy imaging, and energy-dispersive X-ray spectrometry results show that La has been doped successfully into the lattice. The scanning electron microscopy images confirm that all the samples have nearly similar nanoscale porosities. The significant enhancement of electrical conductivity over the broad temperature range has been observed through optimization of La doping. Additionally, the samples possess very low thermal conductivity, which is speculated because of the nanoscale porosity of the samples. Because of this dual mechanism of doping optimization and nanoscale porosity, there is a remarkable improvement in power factor, 1 mW/m²K from 650 to 800 K, and figure of merit, zT of 0.26 at 850 K, of the sample, 22 at. % La-doped SrTiO₃.

Keywords: Doping optimization; Figure of merit; La-doped SrTiO3; Nanoporosity; Surfactant F127.