Oxide Two‐Dimensional Electron Gas with High Mobility at Room‐Temperature
Abstract
The prospect of 2‐dimensional electron gases (2DEGs) possessing high mobility at room temperature in wide‐bandgap perovskite stannates is enticing for oxide electronics, particularly to realize transparent and high‐electron mobility transistors. Nonetheless only a small number of studies to date report 2DEGs in BaSnO3‐based heterostructures. 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 × 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 stannate‐based 2DEGs at application‐relevant temperatures for oxide nanoelectronics.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Feb 20, 2022
- Source ID
- 10.1002/advs.202105652
Entities
People
- Chang-Beom Eom
- Darrell G. Schlom
- Evgeny Y Tsymbal
- Hanjong Paik
- Jinsol Seo
- Kitae Eom
- M. S. Rzchowski
- Neil Campbell
- Sang Ho Oh
Organizations
- Cornell University
- National Science Foundation
- Office of Basic Energy Sciences
- Office of Science
- Sungkyunkwan University
- United States Department of Energy
- University of Nebraska–Lincoln
- University of Wisconsin–Madison