Perovskite ferroelectrics, as an important class of polar optoelectronic materials, have promising applications in the field of nonlinear optics, pyroelectric detection and data storage, etc.
Recently, pure inorganic perovskites (CsPbX3, X = Cl, Br, I) have attracted attention in diverse fields. However, it remains a great challenge to design new cesium-based ferroelectrics.
The research group led by Prof. LUO Junhua at Fujian Institute of Research on the Structure of Matter of the Chinese Academy of Sciences constructed the first two-dimensional bilayered perovskite ferroelectric containing both inorganic alkali metal (Cs) and organic cation, by the alloying the organic cation into the cubic perovskite prototype of CsPbBr3. The study was published in Angew. Chem., Int. Ed. as a very important paper.
Unlike previously-reported hybrid perovskite ferroelectrics, the atomic displacement of inorganic alkali metal Cs+ and the disordered disorder of organic cation synergistically induced the ferroelectric spontaneous polarization for the compound.
Interestingly, this hybrid ferroelectric compound exhibits a high Curie temperature Tc = 412 K, even higher than that of the classic inorganic ferroelectric of BaTiO3 (~393 K).
In addition, the photoelectric devices using the perovskite ferroelectric crystals exhibit very large “on/off” ratios of photoconductivity (> 103). This feature discloses its potential application in the field of photodetection.
This work not only provides a new strategy for designing hybrid perovskite ferroelectrics, but also further expands the researches on ferroelectric mechanisms and optoelectronic applications.
Scheme for inserting organic cation into the cubic CsPbBr3 prototype to form new hybrid perovskite ferroelectric (Image by Prof. LUO’s group)
Contact:
Prof. LUO Junhua
Fujian Institute of Research on the Structure of Matter
Chinese Academy of Sciences
Email: jhluo@fjirsm.ac.cn
