Impact of PN junction inhomogeneity on the piezoelectric fields of acoustic waves in piezo-semiconductive fibers

Kai Fang; Peng Li; Nian Li; Dianzi Liu; Zhenghua Qian; Vladimir Kolesov; Iren Kuznetsova

doi:10.1016/j.ultras.2021.106660

Impact of PN junction inhomogeneity on the piezoelectric fields of acoustic waves in piezo-semiconductive fibers

Ultrasonics. 2022 Mar:120:106660. doi: 10.1016/j.ultras.2021.106660. Epub 2021 Dec 9.

Authors

Kai Fang¹, Peng Li¹, Nian Li¹, Dianzi Liu², Zhenghua Qian³, Vladimir Kolesov⁴, Iren Kuznetsova⁴

Affiliations

¹ State Key Laboratory of Mechanics and Control of Mechanical Structures, College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
² School of Engineering, University of East Anglia, Norwich, UK.
³ State Key Laboratory of Mechanics and Control of Mechanical Structures, College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China. Electronic address: qianzh@nuaa.edu.cn.
⁴ Kotel'nikov Institute of Radio Engineering and Electronics of RAS, Moscow 125009, Russia.

PMID: 34954477
DOI: 10.1016/j.ultras.2021.106660

Abstract

Non-uniform mechanical strain can be easily induced at the interface of a piezoelectric semiconductive (PS) PN junction with variable cross sections by using piezoactive acoustic waves, and thus produces a giant piezoelectric field to significantly enhance the piezotronic effect. For revealing the piezotronic performance modulation in the non-uniform PS PN junction, the electromechanical field under a pair of applied end mechanical forces is studied from perspectives of theoretical analysis and numerical simulations. A one-dimensional linearized model for the PS fiber is established, which is applied for the mechanical analysis of a selected profile with the cross section varying in a specific quadratic function. Numerical results indicate that the acoustoelectric fields in the space charge region of the non-uniform PS PN junction are more sensitive to the applied mechanical forces, compared with that of the uniform junction, especially for a heterogeneous PN junction. Furthermore, the current-voltage relations of a necking PS PN junction can be modulated more easily by the end mechanical forces. Both qualitative conclusions and quantitative results can offer guidance for the piezotronic device design.

Keywords: PN junction; Piezoelectric semiconductor; Variable cross section.