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arXiv · 1211.4778

Optically excited multi-band conduction in LaAlO3/SrTiO3 heterostructures

V. K. Guduru·A. Granados del Aguila·S. Wenderich·M. K. Kruize·A. McCollam·P. C. M. Christianen·U. Zeitler·A. Brinkman·G. Rijnders·H. Hilgenkamp·J. C. Maan
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Abstract

The low-temperature resistance of a conducting LaAlO3/SrTiO3 interface with a 10 nm thick LaAlO3 film decreases by more than 50% after illumination with light of energy higher than the SrTiO3 band-gap. We explain our observations by optical excitation of an additional high mobility electron channel, which is spatially separated from the photo-excited holes. After illumination, we measure a strongly non-linear Hall resistance which is governed by the concentration and mobility of the photo-excited carriers. This can be explained within a two-carrier model where illumination creates a high-mobility electron channel in addition to a low-mobility electron channel which exists before illumination.

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V. K. Guduru, A. Granados del Aguila, S. Wenderich, M. K. Kruize, A. McCollam, P. C. M. Christianen, U. Zeitler, A. Brinkman, G. Rijnders, H. Hilgenkamp, J. C. Maan. 2012-11-20. Optically excited multi-band conduction in LaAlO3/SrTiO3 heterostructures. https://doi.org/10.1063/1.4790844

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