Recent progress in piezo-phototronics with extended materials, application areas and understanding

The coupling effect between different properties in a controllable manner is of great interest for getting full understanding of materials, exploring novel physical phenomena and developing new applications. Piezo-phototronics is an emerging field which explores the three-way coupling among mechanical, optical and electrical properties in materials with noncentrosymmetric crystal structure. It has demonstrated its capability to work on different kinds of optoelectronic devices and can be utilized in various applications. Here, we will give a brief review of the tremendous progress, focusing on extended materials, application areas and understanding in the last two years. New material systems including quantum wells, two-dimensional materials and alloys have been investigated in this field. Novel applications in sonophotocatalysis, flexible electronics, photoluminescence and plasmonics have emerged. Meanwhile, temperature dependence of the piezo-phototronic effect was studied for the first time to gain in-depth understanding of the fundamental physics behind the phenomenon. All of this progress demonstrates the power of this three-way coupling effect in extended fields and shows the growing broader interest in different research areas. (topical review)