journal article·2026-07-01Open access

Tuning the electrical properties of unintentionally doped epitaxial p -type α-SnO thin films while maintaining a shallow hole ionization energy

Seungmin Lee, Anna S. Park, Evan Krysko, Chuan F. C. Chang, Chaojie Du, Viet-Anh Ha, Feliciano Giustino, Xiaoqing Pan, Debdeep Jena, Huili G. Xing, Darrell G. Schlom

APL Materials· Volume 14· Issue 7

Abstract

We demonstrate the growth of unintentionally doped p-type α-SnO (001) thin films by suboxide molecular-beam epitaxy at low growth temperatures of 330–360 °C without additional oxygen supply. By increasing the SnO flux, the hole concentration increases from 0.2 × 1018 to 1.3 × 1018 cm−3, while the hole mobility decreases from 8.5 to 3.9 cm2 V−1 s−1. The dependence of electrical properties on SnO flux is attributed to the associated changes in the chemical potential of SnO during growth, which likely influences the formation of tin vacancies and, therefore, the hole concentration. Similar trends were also observed under an added oxygen background pressure, although the effects were less pronounced. At a fixed SnO flux, the hole mobility increases with increasing growth temperature; however, higher deposition temperature inevitably leads to increased surface roughness. Temperature-dependent Hall measurements reveal a shallow apparent activation energy of 15.2–22.7 meV across the (0.1–8) × 1013 molecules cm−2 s−1 range of SnO fluxes investigated.
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Research context

OpenAlex topics: ZnO doping and properties · Thin-Film Transistor Technologies · Gas Sensing Nanomaterials and Sensors

SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.

Affiliations

Department of Materials Science and Engineering, Cornell University 1 , Ithaca, New York 14853,

Department of Physics, Cornell University 2 , Ithaca, New York 14853,

Department of Materials Science and Engineering, University of California at Irvine 3 , Irvine, California 92697,

Oden Institute for Computational Engineering and Sciences, The University of Texas at Austin 4 , Austin, Texas 78712,

Department of Physics, The University of Texas at Austin 5 , Austin, Texas 78712,

Department of Physics and Astronomy, University of California at Irvine 6 , Irvine, California 92697,

Irvine Materials Research Institute, University of California at Irvine 7 , Irvine, California 92697,

School of Electrical and Computer Engineering, Cornell University 8 , Ithaca, New York 14853,

Kavli Institute at Cornell for Nanoscale Science 9 , Ithaca, New York 14853,

Leibniz-Institut für Kristallzüchtung 10 , Max-Born-Str. 2, Berlin 12489,

Funding

U.S. Department of Energy · Semiconductor Research Corporation · Defense Sciences Office, DARPA · Office of Science · Basic Energy Sciences · National Energy Research Scientific Computing Center

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