Manipulating hot-electron based photovoltage generations at oxide interfaces

ORAL

Abstract

To maximize efficiencies of photovoltaic devices and photodetectors, it is highly desirable to enable carrier excitation from low energy photons and extract excessive energy from hot carriers. At the LaAlO3/SrTiO3 interface contacted by metal electrodes, substantial photovoltages can be generated by photons with energy below the oxide bandgaps. This originates from the photoexcitation of hot carriers in metal and the subsequent charge separations through either hole filtering at the metal/oxide junction or the photothermoelectric effect produced in the interfacial two-dimensional electron gas. The two light-to-voltage conversion mechanisms can be locally selected and reconfigured by patterning of 2DEG using conductive atomic force microscope. With tunable band alignment, improved light absorption and giant Seebeck coefficient at oxide interface, the hot-electron enabled photovoltage generations make LaAlO3/SrTiO3 viable for programmable solar energy harvesting and thermoelectric device applications.

*Work at West Virginia University supported by Department of Energy Grant No. DE-SC-0010399 and National Science Foundation Grant No. NSF-1454950. Work at University of Wisconsin-Madison supported by National Science Foundation DMREF Grant No. DMR-1629270 and AFOSR FA9550-15-1-0334.

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Presenters

  • Dustin Schrecongost

    • West Virginia Univ

Authors

  • Dustin Schrecongost

    • West Virginia Univ

  • Weitao Dai

    • West Virginia Univ

  • Ming Yang

    • West Virginia Univ
    • Physics and Astronomy, West Virginia Univ

  • Hyungwoo Lee

    • University of Wisconsin-Madison
    • Univ of Wisconsin-Madison
    • University of Wisconsin
    • University of Wisconsin–Madison
    • Department of Materials Science and Engineering, University of Wisconsin-Madison
    • Physics, University of Wisconsin–Madison
    • Department of Materials Science and Engineering, University of Wisconsin - Madison

  • Jung-Woo Lee

    • Univ of Wisconsin-Madison
    • University of Wisconsin-Madison
    • University of Wisconsin
    • University of Wisconsin–Madison
    • Physics, University of Wisconsin–Madison
    • Department of Materials Science and Engineering, University of Wisconsin-Madison

  • Chang-Beom Eom

    • University of Wisconsin-Madison
    • Univ of Wisconsin-Madison
    • Univ of Wisconsin, Madison
    • Department of Material Science and Engineering, University of Wisconsin-Madison
    • Matls Sci & Eng, University of Wisconsin-Madison
    • University of Wisconsin
    • Department of Materials Science and Engineering, University of Wisconsin-Madison
    • University of Wisconsin–Madison
    • MS&E, University of Wisconsin
    • Physics, University of Wisconsin–Madison
    • Department of Materials Science and Engineering, University of Wisconsin - Madison

  • Cheng Cen

    • West Virginia Univ
    • University of Wisconsin