Dresden 2017 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 34: Poster session II
MM 34.16: Poster
Dienstag, 21. März 2017, 18:30–20:30, P4
Quantitative High-resolution TEM Imaging of Perovskite Interfaces — •Tobias Meyer1, Patrick Peretzki1, Benedikt Ifland2, Birte Kressdorf2, Christian Jooß2, and Michael Seibt1 — 1IV. Physical Institute, University of Göttingen, Germany — 2Institute for Materials Science, University of Göttingen, Germany
The Shockley-Queisser limit for single junction solar cell efficiencies is based on energy losses due to the transmission of low energy photons with energies below the band gap and the thermalization of hot charge carriers. In strongly correlated perovskite materials, which exhibit polaronic charge carriers, these losses can be reduced at the same time by harvesting long-living intraband excitations. Indeed, during the last decade the efficiency of halide perovskite based solar cells has been increased from 2 % to 20 %. However, the underlying materials are relatively instable – particularly under light illumination. In contrast to halide perovskites, transition-metal oxides are rather stable but their junctions exhibit lower photovoltaic energy conversion efficiencies. Since the electrical transport properties of these materials are highly dependent on the structure, a thorough understanding of the latter close to the interface is exceedingly desirable in order to tune perovskite junctions for photovoltaic applications. We investigated the structure of transition-metal oxide heterojunctions, i.e. the oxygen positions, in an image corrected high-resolution TEM. In order to enhance the contrast of the light oxygen columns, we used optimized conditions for the spherical aberration.