Fundamentals and Applications of ZnO-Nanowire-Based Piezotronics and Piezo-Phototronics

Abstract

The piezotronic effect is a coupling effect of semiconductor and piezoelectric properties. The piezoelectric potential is used to adjust the p-n junction barrier width and Schottky barrier height to control carrier transportation. At present, it has been applied in the fields of sensors, human–machine interaction, and active flexible electronic devices. The piezo-phototronic effect is a three-field coupling effect of semiconductor, photoexcitation, and piezoelectric properties. The piezoelectric potential generated by the applied strain in the piezoelectric semiconductor controls the generation, transport, separation, and recombination of carriers at the metal–semiconductor contact or p-n junction interface, thereby improving optoelectronic devices performance, such as photodetectors, solar cells, and light-emitting diodes (LED). Since then, the piezotronics and piezo-phototronic effects have attracted vast research interest due to their ability to remarkably enhance the performance of electronic and optoelectronic devices. Meanwhile, ZnO has become an ideal material for studying the piezotronic and piezo-phototronic effects due to its simple preparation process and better biocompatibility. In this review, first, the preparation methods and structural characteristics of ZnO nanowires (NWs) with different doping types were summarized. Then, the theoretical basis of the piezotronic effect and its application in the fields of sensors, biochemistry, energy harvesting, and logic operations (based on piezoelectric transistors) were reviewed. Next, the piezo-phototronic effect in the performance of photodetectors, solar cells, and LEDs was also summarized and analyzed. In addition, modulation of the piezotronic and piezo-phototronic effects was compared and summarized for different materials, structural designs, performance characteristics, and working mechanisms’ analysis. This comprehensive review provides fundamental theoretical and applied guidance for future research directions in piezotronics and piezo-phototronics for optoelectronic devices and energy harvesting.

Design and Analysis of a Hybrid Displacement Amplifier Supporting a High-Performance Piezo Jet Dispenser

“…Piezoelectric materials play an important role in the field of flexible electronics [ 1 , 2 , 3 , 4 ], precision engineering [ 5 , 6 , 7 ], and microelectronics packaging [ 8 , 9 , 10 , 11 ]. Piezoelectric materials can deform under the action of electrical flow, which is called piezoelectric effect [ 12 ]. The piezoelectric stacks made by connecting several piezoelectric ceramic pieces in series can efficiently converts electrical energy into mechanical energy.…”

Piezotronic and Piezo-Phototronic Effects-Enhanced Core–Shell Structure-Based Nanowire Field-Effect Transistors

“…Using multi-effect coupling for semiconductor materials to design new electronic devices is an effective means of optimizing device performance and improving the integration of on-chip devices. By utilizing the piezotronic and piezo-phototronic effects, various high-performance electronic and optoelectronic devices can be realized [ 16 , 17 , 18 , 19 , 20 , 21 ]. For example, Yiyao Peng et al prepared a self-powered flexible UV photodetector based on p-GaN/n-ZnO heterostructure, the relative optical response of which can be increased to 22% after applying −0.48% compressive strain under UV irradiation of 38.4 mW/cm 2 [ 21 ].…”