The team of SEU made progress in molecular piezoelectricity
Editor’s notes
Recently, under the funding of "Top Ten Scientific and Technical Issues of Southeast University", the research team of the Key Laboratory of "Molecular Ferroelectric Science and Application" of Jiangsu Province has made important progress in molecular piezoelectricity and discovered the first case of ferrocene-based perovskite piezoelectrics. The related results were published in the Journal of the American Chemical Society, the top journal in the field of chemistry, with the title of "Organometallic-based hybrid perovskite piezoelectrics with narrow band gap".
Research background
The organic-inorganic hybrid perovskite (general formula: ABX3) has been widely concerned for its considerable development potential in high-tech fields such as solar cells, photodetectors, electroluminescence, piezoelectricity, etc. In the field of hybrid perovskite, various piezoelectric and ferroelectric materials with novel structures and excellent performance have emerged because of its excellent structural diversity and chemical adjustability. However, among the hybrid perovskite piezoelectric bodies as reported so far, the A-site components are almost pure organic amine ions.
Since 1951, the advent of ferrocene has set off a revolution in organometallic chemistry. The ferrocene-based organometallic compounds highlight broad application prospects in the fields of nanomedicine, biosensing, catalysis and redox because of their diversity of properties and richness of functions. Upon development of ferrocene-based organometallic compounds for many years, major breakthroughs have been made in the fields of ferromagnetism and ferroelasticity. However, the perovskite piezoelectric materials based on ferrocene-based cations were still a blank before.
Research process and result
As inspired and guided by the "iron electrochemistry" theory (the molecular design principle for ferroelectrics), the research team found it feasible to use ferrocene-based components as cations to replace organic amines, and construct a new type of ferrocene-based perovskite piezoelectric materials: [(Ferrocenylmethyl) trimethylammonium] PbI3 ((FMTMA)PbI3), (FMTMA)PbBr2I and (FMTMA)PbCl2I (Fig. 1).
Thanks to the stability of the ferrocene-based cations, the material's performance has been significantly improved through the halogen control in the anion framework, and excellent piezoelectric properties comparable to LiNbO3 are then obtained with outstanding semiconductor characteristics (Fig. 2). The harvesting devices of piezoelectric energy as prepared based on this material exhibited excellent electromechanical energy conversion performance (Fig. 1b). Such effort has opened a new chapter for studying perovskite piezoelectric materials and will stimulate further research on ferrocene-based perovskite materials.
Notes
It is reported that Zhang Zhixu, a doctoral student from School of Chemistry and Chemical Engineering of Southeast University, is the first author of the paper, Dr. Zhang Hanyue and Prof. Xiong Ren'gen are the corresponding authors, and Southeast University is the first correspondent institute.