Chiral Switchable Low-Dimensional Perovskite Ferroelectrics

• Published in: ACS applied materials & interfaces Vol. 13; no. 1; pp. 2044 - 2051
• Main Authors: Li, Lin-Sui, Tan, Yu-Hui, Wei, Wen-Juan, Gao, Hong-Qiang, Tang, Yun-Zhi, Han, Xiao-Bo
• Format: Journal Article
• Language: English
• Published: United States 13.01.2021
• Subjects: cadmium chloride; dielectric properties; electricity; iron compounds; isotropy; optical isomerism; optical isomers; stoichiometry; ferroelectrics; second-harmonic generation; chirality; dielectric; low-dimensional perovskite
• ISSN: 1944-8244; 1944-8252; 1944-8252
• DOI: 10.1021/acsami.0c19507

Low-dimensional hybrid organic-inorganic perovskites (HOIPs) possess more localized electronic states and narrower conduction and valence bands to promote self-trapping of excitons and stronger exciton emission; therefore, they are widely used as building blocks for various applications in the fields of optoelectronics, photovoltaics, light-emitting diodes, luminescence, fluorescence, and so forth. Despite the past decades of intensive study, the discovered low-dimensional chiral HOIPs are rare as of the 1D chiral HOIP single crystals reported in 2003, as well as the low-dimensional chiral HOIP ferroelectrics are particularly scarce since the first chiral two-dimensional (2D) and/or one-dimensional (1D) HOIP ferroelectrics reported. Herein, two new low-dimensional HOIPs with the same conformational formula [R-MPA] CdCl (R-MPA = ( )-(-)-1-methyl-3-phenylpropylamine) were successfully synthetized by means of regulating the stoichiometric proportion of R-MPA and CdCl in two ways of 1:1 ( ) and 2:1 ( ). By combining single-crystal X-ray diffraction, circular dichroism (CD) spectroscopy, differential scanning calorimetry, temperature-dependent dielectric constant, temperature-dependent second-harmonic generation (SHG) effect, polarization-dependent SHG response, and - hysteresis loop, we reveal that is a 1D nonchiral molecular ferroelectric and is the first zero-dimensional (0D) chiral ferroelectric with distinct CD signals; meanwhile, exhibits increased properties of high- , large dielectric constant, SHG isotropy, and ferroelectricity than that of . These results not only shed light on the high tunability of the low-dimensional HOIP ferroelectrics but also open up an avenue to explore multifunctional chiral ferroelectrics.