东南大学熊仁根团队报道了二维杂化钙钛矿铁电体的大电致伸缩系数。 相关研究成果于2021年1月15日发表于国际一流学术期刊《美国化学会杂志》。

二维有机-无机钙钛矿杂化材料（HOIPs）因其在光电领域的巨大科技潜力而受到广泛关注。虽然2D-HOIPs的铁电性已经得到了很大的发展，但是迄今为止还没有发现膦基2D-HOIPs铁电体。同时，电致伸缩在铁电体的机电行为中起着重要的作用，而对于2D-HOIP铁电体的电致伸缩作用还未见报道。

该文中，研究人员提出了第一个直接带隙为2.84ev的膦基2D-HOIP铁电（EATMP）PbBr4（EATMP=（2-aminoethyl)trimethylphosphanium）。值得注意的是，（EATMP）PbBr4的居里温度高达534K，是所有报道的2D-HOIP铁电体中最高的。其电致伸缩系数约为3.96m⁴C^-2，远高于PVDF（1.3m⁴C^-2）和无机材料（0.034-0.096m⁴C^-2）。

(EATMP)PbBr4具有优良的铁电、压电性能和易于加工等优点，在未来的智能器件、传感器、执行器等领域有着广阔的应用前景。

附：英文原文

Title: Large Electrostrictive Coefficient in a Two-Dimensional Hybrid Perovskite Ferroelectric

Author: Han-Yue Zhang, Zhi-Xu Zhang, Xiao-Gang Chen, Xian-Jiang Song, Yi Zhang, Ren-Gen Xiong

Issue&Volume: January 15, 2021

Abstract: Two-dimensional (2D) hybrid organic–inorganic perovskites (HOIPs) are attracting tremendous interest for their great scientific and technological potential in photovoltaics and optoelectronics. Although the ferroelectricity in 2D HOIPs has been greatly developed, however, to date no phosphonium-based 2D HOIP ferroelectrics have yet been found. Meanwhile, electrostriction plays an important role in the electromechanical behavior of ferroelectrics, while it has never been reported for 2D HOIP ferroelectrics. Here, we present the first phosphonium-based 2D HOIP ferroelectric (EATMP)PbBr4 (EATMP = (2-aminoethyl)trimethylphosphanium) with a direct bandgap of 2.84 eV. Notably, (EATMP)PbBr4 possesses a high Curie temperature of 534 K, which is the highest among all reported 2D HOIP ferroelectrics. Moreover, it exhibits a large electrostrictive coefficient of about 3.96 m4 C–2 as well, far exceeding those of PVDF (1.3 m4 C–2) and inorganic ones (～0.034–0.096 m4 C–2). With excellent ferroelectric and piezoelectric properties and the merit of easy fabrication, (EATMP)PbBr4 shows great potential in applications for future smart devices of actuators, transducers, and sensors.

DOI: 10.1021/jacs.0c12907

Source: https://pubs.acs.org/doi/10.1021/jacs.0c12907