Tailoring oxide surfaces and interfaces for energy conversion applications
Rossitza Pentcheva, University of Duisburg-Essen, Duisburg, GermanyBenjamin Geisler, University of Duisburg-Essen, Duisburg, GermanyHamidreza Hajiyani, University of Duisburg-Essen, Duisburg, Germany
Transition metal oxides are promising materials for energy conversion applications due to their chemical and thermal stability, environmental friendliness and in particular to their complex electronic behavior. Based on the insight from first principles calculations including an on-site Hubbard term, we address examples for the optimization of oxide thermoelectrics and anode materials for water splitting. In conjunction with Boltzmann transport theory we explore the implications of interface polarity and confinement on the thermoelectric properties of nickelate superlattices: In particular, compatible n- and p-type materials can be realized by selective choice of the layer stacking at the polar interfaces of LaNiO3/SrTiO3(001) superlattices . Moreover, a strongly enhanced thermoelectric response is obtained in nonpolar LaNiO3/LaAlO3(001) superlattices as a consequence of the metal-to-insulator transition driven by confinement . Last but not least, we explore the effect of surface orientation, termination and cation substitution on the performance of the hematite as an anode material in the oxygen evolution reaction.
Funding by the DFG within CRC/TRR80 and TRR247 and SPP1613, and computational time at the Leibniz Rechenzentrum and MagnitUDE are gratefully acknowledged.
 B. Geisler, A. Blanca-Romero and R. Pentcheva, Phys. Rev. B 95, 125301 (2017)
 B. Geisler and R. Pentcheva, Phys. Rev. Materials 2, 055403 (2018).
 A.G. Hufnagel, H. Hajiyani, S. Zhang, T. Li, O. Kasian, B. Gault, B. Breitbach, T. Bein, D. Fattakhova-Rohlfing, C. Scheu, R. Pentcheva, Adv. Funct. Mater. 1804472 (2018).