Alloying Small‐Cation into Low‐Dimensional Perovskite Motif Gives Multiaxial Ferroelectrics with Enhanced Photo‐Pyroelectricity

, thus giving its multiaxial ferroelectricity with 6 equivalent polarization directions. Strikingly, 1 exhibits photo-pyroelectricity in a broad ultraviolet-to-NIR spectral range (266-980 nm), which couples with ferroelectric bulk photovoltaics to create giant photocurrent enhancement ratio of ∼4800%. This merit far surpasses those of known ferroelectric materials. These results shed light on the design of new photoactive ferroelectric candidates for smart photoelectronic device applications.