Using a combination of vertical transport measurements across and lateral transport measurements along the LaAlO3/SrTiO3 heterointerface, we demonstrate that significant potential barrier lowering and band bending are the cause of interfacial metallicity. Barrier lowering and enhanced band bending extends over 2.5 nm into LaAlO3 as well as SrTiO3. We explain origins of high-temperature carrier saturation, lower carrier concentration, and higher mobility in the sample with the thinnest LaAlO3 film on a SrTiO3 substrate. Lateral transport results suggest that parasitic interface scattering centers limit the low-temperature lateral electron mobility of the metallic channel.
@article{arxiv.0809.0926,
title = {Potential barrier lowering and electrical transport at the LaAlO$_{3}$/SrTiO$_{3}$ heterointerface},
author = {Franklin J. Wong and Miaofang Chi and Rajesh V. Chopdekar and Brittany B. Nelson-Cheeseman and Nigel D. Browning and Yuri Suzuki},
journal= {arXiv preprint arXiv:0809.0926},
year = {2008}
}