JACS: Soft multiaxial molecular ferroelectric thin films with self-powered broadband photodetection

• Molecular ferroelectric thin films provide a good platform for miniaturized electronic devices, which is inseparable from their multiaxiality. Despite extensive research, soft MFFs with broadband optoelectronic activity are still a huge gap, because photo-excited leakage currents severely deteriorate ferroelectricity, hindering their optoelectronic applications.
  

• Recently, Zhihua Sun and Junhua Luo from Fujian Institute of Physics, Chinese Academy of Sciences constructed a multiaxial MFF of HA2EA2Pb3I10 (where EA = ethylammonium, HA = n-hexylammonium) in 2D multilayer perovskite. The researchers observed eight equivalent polarization directions in HA2EA2Pb3I10, as evidenced by its symmetry breaking (i.e., 4/mmmFm species), which is the largest among 2D multilayer perovskites, even exceeding Classic ceramic BaTiO3.
  

• In particular, the researchers found that spin-coated flexible MFFS of HA2EA2Pb3I10, oriented approximately parallel to the layered perovskite framework, exhibited in-plane spontaneous polarization (Ps = 1.8 μC/cm2) and broadband absorption (∼1.83 eV). Furthermore, self-powered broadband detection (0.55 μA/cm2 under 637 nm illumination) was achieved on the soft films, revealing their potential in flexible and wearable electronics. The research results shed light on the design of flexible optoelectronic devices and provide an effective way to expand the application of 2D molecular ferroelectric materials.
  

• 

• Shiguo Han, et al, Soft Multiaxial Molecular Ferroelectric Thin Films with Self-Powered Broadband Photodetection, J. Am. Chem. Soc., 2022 DOI: 10.1021/jacs.2c07892 https://doi.org/10.1021/jacs.2c07892