Correlated metals as transparent conductors

Lei Zhang; Yuanjun Zhou; Lu Guo; Weiwei Zhao; Anna Barnes; Hai-Tian Zhang; Craig Eaton; Yuanxia Zheng; Matthew Brahlek; Hamna F Haneef; Nikolas J Podraza; Moses H W Chan; Venkatraman Gopalan; Karin M Rabe; Roman Engel-Herbert

doi:10.1038/nmat4493

Correlated metals as transparent conductors

Nat Mater. 2016 Feb;15(2):204-10. doi: 10.1038/nmat4493. Epub 2015 Dec 14.

Authors

Lei Zhang^{1

2}, Yuanjun Zhou³, Lu Guo^{1

2}, Weiwei Zhao⁴, Anna Barnes^{5

6}, Hai-Tian Zhang^{1

2}, Craig Eaton^{1

2}, Yuanxia Zheng^{1

2}, Matthew Brahlek^{1

2}, Hamna F Haneef^{5

6}, Nikolas J Podraza^{5

6}, Moses H W Chan⁴, Venkatraman Gopalan¹, Karin M Rabe³, Roman Engel-Herbert^{1

2}

Affiliations

¹ Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
² Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
³ Department of Physics and Astronomy, Rutgers University, Rutgers, New Jersey 08854, USA.
⁴ Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
⁵ Department of Physics and Astronomy, University of Toledo, Toledo, Ohio 43606, USA.
⁶ Wright Center for Photovoltaics Innovation and Commercialization, University of Toledo, Toledo, Ohio 43606, USA.

PMID: 26657329
DOI: 10.1038/nmat4493

Abstract

The fundamental challenge for designing transparent conductors used in photovoltaics, displays and solid-state lighting is the ideal combination of high optical transparency and high electrical conductivity. Satisfying these competing demands is commonly achieved by increasing carrier concentration in a wide-bandgap semiconductor with low effective carrier mass through heavy doping, as in the case of tin-doped indium oxide (ITO). Here, an alternative design strategy for identifying high-conductivity, high-transparency metals is proposed, which relies on strong electron-electron interactions resulting in an enhancement in the carrier effective mass. This approach is experimentally verified using the correlated metals SrVO3 and CaVO3, which, despite their high carrier concentration (>2.2 × 10(22) cm(-3)), have low screened plasma energies (<1.33 eV), and demonstrate excellent performance when benchmarked against ITO. A method is outlined to rapidly identify other candidates among correlated metals, and strategies are proposed to further enhance their performance, thereby opening up new avenues to develop transparent conductors.