Correlated metals as transparent conductors.

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.

Highly Conductive SrVO3 as a bottom electrode for functional perovskite oxides.

Stoichiometric SrVO3 thin films grown by hybrid molecular beam epitaxy are demonstrated, meeting the stringent requirements of an ideal bottom electrode material. They display an order of magnitude lower room temperature resistivity and superior chemical stability, compared to the commonly employed SrRuO3 , as well as atomically smooth surfaces. Excellent structural compatibility with perovskite and related structures renders SrVO3 a high performance electrode material with the potential to promote the creation of new functional oxide electronic devices.