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Band Structure Engineering at Heterojunction Interfaces via the Piezotronic Effect

Authors

  • Jian Shi,

    1. Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
    Current affiliation:
    1. These authors contributed equally to this work.
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  • Matthew B. Starr,

    1. Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
    Current affiliation:
    1. These authors contributed equally to this work.
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  • Xudong Wang

    Corresponding author
    1. Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
    • Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA.
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Abstract

Engineering the electronic band structure using the piezopotential is an important aspect of piezotronics, which describes the coupling between the piezoelectric property and semiconducting behavior and functionalities. The time-independent band structure change under short-circuit condition is believed to be due to the remnant piezopotential present at the interface, a result of the finite charge-screening depth at the interface. A series of materials, including metals, semiconductors and electrolytes, are selected to investigate the interfacial band structure engineered by remnant piezopotential when they are in contact with a strained piezoelectric semiconductor. The remnant piezopotential at the interface can switch the junction between Ohmic and Schottky characters, enhance charge combination/separation, regulate barrier height, and modulate reaction kinetics. The difference between the regular time-dependent, pulse-type piezopotential and constant remnant piezopotential is also discussed in detail using a ZnO-based photoelectrochemical anode as an example. The piezotronic effect offers a new pathway for engineering the interface band structure without altering the interface structure or chemical composition, which is promising for improving the performance of many electronics, optoelectronics, and photovoltaic devices.

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