TY - JOUR

T1 - Engineering surface dipoles on mixed conducting oxides with ultra-thin oxide decoration layers

AU - Siebenhofer, Matthäus

AU - Nenning, Andreas

AU - Rameshan, Christoph

AU - Blaha, Peter

AU - Fleig, Jürgen

AU - Kubicek, Markus

N1 - Publisher Copyright: © The Author(s) 2024.

PY - 2024/2

Y1 - 2024/2

N2 - Improving materials for energy conversion and storage devices is deeply connected with an optimization of their surfaces and surface modification is a promising strategy on the way to enhance modern energy technologies. This study shows that surface modification with ultra-thin oxide layers allows for a systematic tailoring of the surface dipole and the work function of mixed ionic and electronic conducting oxides, and it introduces the ionic potential of surface cations as a readily accessible descriptor for these effects. The combination of X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) illustrates that basic oxides with a lower ionic potential than the host material induce a positive surface charge and reduce the work function of the host material and vice versa. As a proof of concept that this strategy is widely applicable to tailor surface properties, we examined the effect of ultra-thin decoration layers on the oxygen exchange kinetics of pristine mixed conducting oxide thin films in very clean conditions by means of in-situ impedance spectroscopy during pulsed laser deposition (i-PLD). The study shows that basic decorations with a reduced surface work function lead to a substantial acceleration of the oxygen exchange on the surfaces of diverse materials.

AB - Improving materials for energy conversion and storage devices is deeply connected with an optimization of their surfaces and surface modification is a promising strategy on the way to enhance modern energy technologies. This study shows that surface modification with ultra-thin oxide layers allows for a systematic tailoring of the surface dipole and the work function of mixed ionic and electronic conducting oxides, and it introduces the ionic potential of surface cations as a readily accessible descriptor for these effects. The combination of X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) illustrates that basic oxides with a lower ionic potential than the host material induce a positive surface charge and reduce the work function of the host material and vice versa. As a proof of concept that this strategy is widely applicable to tailor surface properties, we examined the effect of ultra-thin decoration layers on the oxygen exchange kinetics of pristine mixed conducting oxide thin films in very clean conditions by means of in-situ impedance spectroscopy during pulsed laser deposition (i-PLD). The study shows that basic decorations with a reduced surface work function lead to a substantial acceleration of the oxygen exchange on the surfaces of diverse materials.

UR - http://www.scopus.com/inward/record.url?scp=85186233692&partnerID=8YFLogxK

U2 - 10.1038/s41467-024-45824-9

DO - 10.1038/s41467-024-45824-9

M3 - Article

C2 - 38409206

AN - SCOPUS:85186233692

VL - 15.2024

JO - Nature Communications

JF - Nature Communications

SN - 2041-1723

IS - 1

M1 - 1730

ER -