Separation of the piezotronic and piezoresistive effects in a zinc oxide nanowire

Abstract

The strain-induced band structure change in a semiconductor can change its resistivity, known as the piezoresistive effect. If the semiconductor is also a piezoelectric material, strain-induced polarization charge can control the current transport at the metal-semiconductor contact, which is called a 'piezotronic effect'. Piezotronic effect is intertwined with piezoresistive effect in the study of present piezotronic nanowire devices. Decoupling those effects will facilitate the fundamental study on the piezotronic devices and simplify the data analysis in real applications. Here, we report a general method to separate the piezotronic and piezoresistive effects in the same nanowire, based on modified four-point measurements. Current transport characteristics of each contact was extracted and showed different responses to the strain. The piezoresistive effect was measured in zinc oxide nanowires for the first time, and the result confirmed the dominant role of piezotronic effect in the strain-induced change of transport characteristics in a piezoelectric semiconductor. This study validates the assumption made in present piezotronic devices and provides a guideline for further investigation.

Piezotronic Effect: An Emerging Mechanism for Sensing Applications

“…The piezoresistive effect describes a change of the electrical conductivity of a semiconductor or metal when strain alters its bandgap, and thus it is a volume effect. Usually, the piezotronic effect has a more significant influence on the current flow than the piezoresistive effect when a Schottky barrier exists [ 45 ].…”

Morphological and spectroscopic studies on the vertically aligned zinc oxide nanorods grown on low and high temperature deposited seed layer

“…ZnO nanostructures show unique properties as compared to its bulk form. These nanostructures exists in many forms, 0-dimensional quantum dots [2], 1-dimensional nanowires, nanorods, nanoribbons [3][4][5], 2-dimensional nanoplasts, nanodiscs [6,7] and 3-dimensional nanofoam, nanoflowers etc. [8][9][10].…”

AFM investigation of nanomechanical properties of ZnO nanowires

“…Over the decades, lots of nanodevices based on ZnO nanowires (NWs), nanobelts (NBs), nanorods, and nanoarrays have been fabricated which relied on their remarkable semiconducting, electrical, photoelectric, piezoelectric, electromechanical, chemical stability, biocompatibility, and non-toxic properties. However, most researchers focus on the physical performances of nanodevices at present, [12][13][14][15][16][17][18] while few researchers focus on mechanical service behaviors of nanomaterials and nanodevices. [1][2][3][4][5][6][7][8][9] Nanodevices based on piezoelectric and electromechanical properties need the drive of continuous, periodic external forces or loads, and the efficiencies are related to the size and rate of external forces.…”