Recently, the photoflexoelectric effect in the semiconductor materials has been discovered for the first time by Researcher Huang Wenbin from the School of Mechanical Engineering of Chongqing University in collaboration with Associate Professor Shu Longlong from Nanchang University. Their findings were published in Nature Materials (factor of influence: 38.8), a top international academic journal, under the title “Giant photoflexoelectric effect in halide perovskites”. Huang Wenbin is the first co-author. Doctoral Candidate Wang Zhiguo has also made remarkable contributions. This marks a significant achievement made by Chongqing University in interdisciplinary fusion of mechanical engineering.

Flexoelectric effect is a kind of electrode effect produced by gradient strain, which is a new type of electromechanical coupling effect gradually emerging in recent years. Different from piezoelectric effect, flexoelectric effect has many advantages. It is not limited by crystal symmetry, and has small size effect (that is, the smaller the size is, the stronger the effect is), making it promising in application in areas like structural health monitoring, energy collection and many other fields.

In this paper, the flexoelectric properties of halogenated perovskite are studied for the first time. It has been found that this photovoltaic semiconductor material has a very special flexoelectric effect, and its flexoelectric coefficient is greatly enhanced under the action of light. Furthermore, the physical mechanism of the photorefractive effect is studied in depth, which indicates that the photorefractive effect is a common physical phenomenon in all light absorbing materials. Optical flexoelectric effect can be utilized to realize the coupling of optical, mechanical and electrical multi-physical fields. It can collect the mechanical energy and light energy in the environment at the same time. It provides a new way to solve the problem related to environmental energy collection that hinders the development of the Internet of things.

Huang Wenbin is a talent recruited by Chongqing University in 2015 under the “One-hundred Talents Program”. He works as a full-time researcher at the State Key Lab of Mechanical Transmissions, Chongqing University and is mainly engaged in basic research in areas like intelligent materials and structure. His research findings have been preliminarily used in areas like rail transit, special vehicles and wind power generation.

Link of the full paper:https://www.nature.com/articles/s41563-020-0659-y