2015/07/07 by Z. Huang, Zhen Huang, Kun Han +17 · 50 citations
Chemistry · Engineering · Materials Science · Physics and Astronomy · #Chemical physics #Chemistry #Condensed matter physics #Electron mobility #Electronic and Structural Properties of Oxides #Lattice (music) #Magnetic and transport properties of perovskites and related materials #Materials science #Optoelectronics #Oxide #Physics #Polar #Semiconductor materials and devices #cond-mat.mtrl-sci #cond-mat.str-el
paper · pdf · doi:10.1021/acs.nanolett.5b04814
published in Nano Letters 16(4), 2307-2313 (American Chemical Society) · 17 pages, 4 figures
arxiv created 2015/07/07 · openalex publication_date 2016/03/09 · arxiv updated 2016/03/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Since the discovery of two-dimensional electron gas (2DEG) at the oxide interface of LaAlO3/SrTiO3 (LAO/STO), improving carrier mobility has become an important issue for device applications. In this paper, by using an alternate polar perovskite insulator (La0.3Sr0.7) (Al0.65Ta0.35)O3 (LSAT) for reducing lattice mismatch from 3.0% to 1.0%, the low-temperature carrier mobility has been increased 30 fold to 35,000 cm(2) V(-1) s(-1). Moreover, two critical thicknesses for the LSAT/STO (001) interface are found, one at 5 unit cells for appearance of the 2DEG and the other at 12 unit cells for a peak in the carrier mobility. By contrast, the conducting (110) and (111) LSAT/STO interfaces only show a single critical thickness of 8 unit cells. This can be explained in terms of polar fluctuation arising from LSAT chemical composition. In addition to lattice mismatch and crystal symmetry at the interface, polar fluctuation arising from composition has been identified as an important variable to be tailored at the oxide interfaces to optimize the 2DEG transport.