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 (Ps = 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.

Broadband photodetection has shown a great promise for diverse applications, while the realization of plateau photoresponse from ultraviolet (UV) to nearinfrared (NIR) spectral region is very challenging. Herein, we exploit photoexcited pyroelectric effect in a chiral hybrid perovskite, (N, N-dimethylcyclohexylammonium)PbBr 3 (1), serving as a new pathway to drive broadband photoactivities. It is a room-temperature pyroelectric with large polarization of � 6.4 μC cm À 2 and high pyroelectric figure-of-merits (F V = 1.0 × 10 À 2 cm 2 μC À 1 and F D = 7.1 × 10 À 5 Pa À 1/2 ). Strikingly, light-induced pyroelectric effect arising from spontaneous polarization is observed in 1, which cover UV (266 nm) to NIR-II (1950 nm) full spectral region. The broadband photoresponses actualized by pyroelectricity break the limit of optical band gap. As the first demonstration of photo-pyroelectricity covering UV-to-NIR spectral region in hybrid perovskites, this work paves a pathway to assemble high-performance smart devices.