Soft Multiaxial Molecular Ferroelectric Thin Films with Self-Powered Broadband Photodetection

Shiguo Han; Yu Ma; Lina Hua; Liwei Tang; Beibei Wang; Zhihua Sun; Junhua Luo

doi:10.1021/jacs.2c07892

Soft Multiaxial Molecular Ferroelectric Thin Films with Self-Powered Broadband Photodetection

J Am Chem Soc. 2022 Nov 9;144(44):20315-20322. doi: 10.1021/jacs.2c07892. Epub 2022 Oct 28.

Authors

Shiguo Han^{1

2}, Yu Ma^{1

2}, Lina Hua^{1

2}, Liwei Tang^{1

2}, Beibei Wang^{1

2}, Zhihua Sun^{1

2}, Junhua Luo^{1

3

2

4}

Affiliations

¹ State Key Laboratory of Structure Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, P. R. China.
² Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou 350002, P. R. China.
³ School of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330022, P. R. China.
⁴ University of Chinese Academy of Sciences, Beijing 100049, P. R. China.

PMID: 36305794
DOI: 10.1021/jacs.2c07892

Abstract

Molecular ferroelectric films (MFFs) offer a good platform for miniaturized electronic devices, which are inseparable from their multiaxial nature. Despite great studies, soft MFFs with broadband photo-electroactivity still remain a huge blank as the photoexcited leakage current will severely deteriorate ferroelectricity, hindering their optoelectronic applications. Here, we constructed the multiaxial MFF of HA₂EA₂Pb₃I₁₀ (1, where EA = ethylammonium and HA = n-hexylammonium) in 2D multilayered perovskites. Eight equivalent polarization directions were observed in 1, as verified by its symmetry breaking (i.e., 4/mmmFm species), which is the maximum among 2D multilayered perovskites and even more than that of classic ceramic BaTiO₃. Specially, spin-coated flexible MFFs of 1 are approximately orientated parallel to layered perovskite frameworks, exhibiting in-plane spontaneous polarization (P_s = 1.8 μC/cm²) and broadband absorption (∼1.83 eV). In addition, self-powered broadband detection (∼0.55 μA/cm² at 637 nm illumination) was achieved on the soft films, revealing their potential for flexible and wearable electronic devices. Our result sheds light on the design of flexible photoelectronic devices and provides an effective way to expand the applications of 2D molecular ferroelectric materials.