Regensburg 2010 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 26: Poster Session
MM 26.68: Poster
Dienstag, 23. März 2010, 14:45–16:30, Poster C
Electrical characterisation of oxide-pn-junctions under illumination — •Gesine Saucke1, Benedikt Ifland1, Constanze Thees1, Jonas Norpoth1, Jörg Hoffmann1, Yimei Zhu2, and Christian Jooss1 — 1Institute of Materials Physics, University of Göttingen, Germany — 2Brookhaven National Laboratory, Upton NY, USA
Correlation effects in complex oxide materials should strongly affect the properties of a pn-junction with respect to energy conversion under illumination. As a model system of a photo-active oxide junction, epitaxial thin films of p-type Pr1−xCaxMnO3 (PCMO) were deposited on Nb doped SrTiO3 (Nb-STO) single crystals. Low-resistance ohmic contacts on Nb-STO were obtained for deposited Ti or Al top layers, whereas high work function noble metals reveal non-linear IV characteristics. Since correlation effects, e.g. charge ordering in PCMO, takes place at lower temperatures, the electric characterization with and without illumination via IV curves was performed in a temperature range between 10 K and room temperature. A detailed characterization with respect to crystallographic structure, surface morphology, and interface intermixing was performed by means of TEM, AFM, SIMS and EELS. We found a small Ti-Mn exchange at the PCMO/Nb-STO interface which extends over a few lattice cells. In addition, we will present first results on p-type La1−xSrxMnO3 (LSMO) / Nb-STO based cells.