Design of wide bandgap Al<sub>2</sub>O<sub>3</sub>/BaSnO<sub>3</sub>quantum well

ORAL

Abstract

Quantum wells are made up of a larger bandgap “barrier” material sandwiching the smaller bandgap “well” material. Typically made of semiconductors, they are used as lasers, photodetectors, modulators, and other devices. BaSnO3 has very high mobility (150cm^2/V-s for thin film) and a wide bandgap(~3.1eV) which makes it a great candidate for the transparent conductive films material which has applications such as electrodes for optical devices, solar cells and light emitting diodes. We report a quantum well with a large conduction band offset of 3.5eV comprising  as a “barrier” material and BSO as a “well” material. The small conduction band offset (less than 1eV) of semiconductor quantum wells only allows for intersubband transitions at a mid or far infrared range. The oxide quantum well allows intersubband transitions from visible to infrared range. Using molecular beam epitaxy, we grow quantum well structures and use reflection-energy electron diffraction (RHEED), X-ray photoelectron spectroscopy (XPS) and scanning transmission electron microscopy to confirm the film quality and composition. We have explored quantum wells with three BSO different thickness to observe the blue shift of the absorption edge due to quantum confinement using ellipsometry.

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Publication: Choi, M., Lin, C., Butcher, M., Rodriguez, C., He, Q., Posadas, A. B., Borisevich, A. Y., Zollner, S., & Demkov, A. A. (2015). Quantum confinement in transition metal oxide quantum wells. Applied Physics Letters, 106(19), 192902. https://doi.org/10.1063/1.4921013

J. E. Ortmann, N. Nookala, Q. He, L. Gao, C. Lin, A. B. Posadas, A. Y. Borisevich, M. A. Belkin, and A. A. Demkov, ACS NANO 12, 7682 (2018)
Ortmann, J. E., Duncan, M. A., & Demkov, A. A. (2019). Designing near-infrared electro-optical devices from the SrTiO3/LaAlO3 materials system. Optical Materials Express, 9(7), 2982. doi:10.1364/ome.9.002982

Presenters

  • Suyeong Jang

    • University of Texas at Austin

Authors

  • Suyeong Jang

    • University of Texas at Austin

  • Wei Guo

    • University of Texas at Austin

  • Jamie Warner

    • Walker Department of Mechanical Engineering, University of Texas at Austin
    • University of Texas at Austin

  • Stefan Zollner

    • New Mexico State University

  • Agham Posadas

    • Department of Physics, University of Texas at Austin
    • University of Texas at Austin

  • Hyoju Park

    • Walker Department of Mechanical Engineering, University of Texas at Austin
    • University of Texas at Austin

  • Wente Li

    • Department of Physics University of Texas at Austin
    • University of Texas at Austin

  • Alexander A Demkov

    • University of Texas at Austin
    • Department of Physics, University of Texas at Austin