Piezotronic Effect: An Emerging Mechanism for Sensing Applications

Abstract

Strain-induced polarization charges in a piezoelectric semiconductor effectively modulate the band structure near the interface and charge carrier transport. Fundamental investigation of the piezotronic effect has attracted broad interest, and various sensing applications have been demonstrated. This brief review discusses the fundamentals of the piezotronic effect, followed by a review highlighting important applications for strain sensors, pressure sensors, chemical sensors, photodetectors, humidity sensors and temperature sensors. Finally, the review offers some perspectives and outlook for this new field of multi-functional sensing enabled by the piezotronic effect.

Piezoelectric-conductor iterative method for analysis of cracks in piezoelectric semiconductors via the finite element method

“…Then, taking the electric field strength 0 E , electric 13 current 0 J , and carrier density n to be in the far field, they have the following relationship: …”

Lithography-free microfabrication of AlGaN/GaN 2DEG strain sensors using laser ablation and direct wire bonding

“…The R 2 values around 0.96 to 0.99 for four different linear fitting curves showed the proportional (linear) trend of current change with respect to the applied displacements. In addition, the sensitivity increases with an increase in V bias , which is a general trend of devices using a Schottky contact [16][17][18]. To characterize transient response of the fabricated sensor, the real-time current change was monitored with different levels of displacement applied and released alternatively, as shown in Fig.…”

Numerical study of near-optimal parameters of polymeric encapsulation layer containing a periodic array of piezoelectric nanowires used for force sensing

“…Piezoelectric nanowire arrays constitute an attractive ultralow power (or even fully self-powered) large-area pressure sensing solution, which offers the possibility of very high spatial resolution, e.g. even exceeding that of mechanoreceptors in the human hand [1]. Due to abundancy of mechanical stimuli in the environment such nanowire-based pressure sensors are promising candidates in a variety of applications including e-skin [5,6], fingerprint scanning [7], electrical triggering [8], etc.…”

“…PZT, BaTiO3, NaNbO3, LiNbO3), transition metal dichalcogenide (MoS2) monolayers, piezoelectric polymers (e.g. PVDF) and nanocomposites as well as organic materials such as diphenylalanine peptide [1][2][3][4]. ZnO is the most widely used material in the field of "piezotronics" with nanowires being the most commonly used structure, which is implemented either in singlenanowire or arrayed configuration.…”

“…nanoparticles, nanodots), 1D (e.g. nanowires, nanotubes, nanofibers) or 2D (nanofilms), have been recently implemented to perform optical, (bio)chemical, gas, humidity, temperature, strain, force or pressure sensing functions [1][2].…”