Dataset: Oxide Two-Dimensional Electron Gas with High Mobility at Room-Temperature

Kitae Eom¹, Hanjong Paik^2,3, Jinsol Seo⁴, Neil Campbell⁵, Evgeny Y. Tsymbal⁶, Sang Ho Oh⁴, Mark S. Rzchowski⁵, Darrell G. Schlom^2,7,8, Chang-Beom Eom<sup>1

1</sup>Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
²Department of Materials Science and Engineering, Cornell University, Ithaca, NY 14853, USA
³Platform for the Accelerated Realization, Analysis, and Discovery of Interface Materials (PARADIM), Cornell University, Ithaca, NY, 14853, USA
⁴Department of Energy Science, Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea
⁵Department of Physics, University of Wisconsin, Madison, WI, 53706, USA
Department of Physics and Astronomy, University of Nebraska, Lincoln, NE, 68588, USA
⁷Kavli Institute at Cornell for Nanoscale Science, Ithaca, NY 14850, USA
⁸Leibniz-Insitut für Kristallzüchtung, Berlin, 12489, Germany

The prospect of 2-dimensional electron gases (2DEGs) possessing high mobility at room temperature in wide-band gap perovskite stagnates is enticing for oxide electronics, particularly to realize transparent and high-electron mobility transistors. Nonetheless only a small number of studies to date report 2DEGsin BaSnO₃-based heterostructure. Here, 2DEG formation at the LaScO₃/BaSnO₃ (LSO/BSO) interface with a room-temperature mobility of 60 cm² V^-1 s^-1 at a carrier concentration of 1.7 x 10¹³ cm^-2 is reported. This is an order of magnitude higher mobility at room temperature than achieved in SrTiO₃-based 2DEGs. This is achieved by combining a thick BSO buffer layer with an ex situ high-temperature treatment, which not only reduces the dislocation density but also produces a SnO₂-terminated atomically flat surface, followed by the growth of an overlying BSO/LSO interface. Using weak beam dark-field transmission electron microscopy imaging and in-line electron holography technique, a reduction of the threading dislocation density is revealed, and direct evidence for the spatial confinement of a 2DEG at the BSO/LSO interface is provided. This work opens a new pathway to explore the exciting physics of stagnate-based 2DEGs at application-relevant temperatures for oxide nanoelectronics.