Auxetic piezoelectric effect in heterostructures.
Ming-Min Yang1,2,3, Tian-Yuan Zhu4,5, Arne Benjamin Renz6
1Department of Physics, The University of Warwick, Coventry, UK. mingminyang@hfnl.cn.
Nature Materials
|November 30, 2023
Summary
Interface symmetry engineering enables an auxetic piezoelectric effect, causing simultaneous expansion or contraction in all directions. This novel electromechanical coupling has broad applications in semiconductor devices.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Nanotechnology
Background:
- Interface symmetry breaking drives diverse physical phenomena like spin-charge conversion and photovoltaic effects.
- Interface asymmetry can induce piezoelectricity in heterostructures, including those with centrosymmetric semiconductors, enabling electromechanical coupling.
- Piezoelectric effects are crucial for actuators, sensors, and filters.
Purpose of the Study:
- To engineer interface symmetry to achieve novel piezoelectric phenomena.
- To demonstrate an electrical analogue of the negative Poisson's ratio in piezoelectric heterostructures.
- To explore the potential of this effect for advanced semiconductor applications.
Main Methods:
- Targeted engineering of interface symmetry in semiconductor heterostructures.
- Characterization of longitudinal (d33) and transverse (d31, d32) piezoelectric coefficients.
- Tuning of transverse coefficients via in-plane symmetry anisotropy.
Main Results:
- Achieved piezoelectric phenomena analogous to negative Poisson's ratio, termed the auxetic piezoelectric effect.
- Observed simultaneous contraction or expansion in all directions under electrical stimulus due to consistent signs of piezoelectric coefficients.
- Demonstrated tunability of transverse coefficients through in-plane symmetry.
Conclusions:
- The auxetic piezoelectric effect offers a new paradigm for electromechanical coupling.
- This effect is achievable across various material systems with substantial coefficients.
- Potential applications include all-semiconductor actuators, sensors, and filters.
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