Durable Photo‐Pyroelectric Detection in a Diamine‐Constructed Lead‐Free Hybrid Perovskite Ferroelectric

Abstract As a subcategory of pyroelectric materials, hybrid perovskite ferroelectrics possess substantial pyroelectric properties and exceptional light absorption characteristics, demonstrating significant potential in the photo‐pyroelectric (PPE) detection field. Despite the significant advantages of hybrid perovskite ferroelectric materials for PPE detection, both the lead issue and the weak stability from van der Waals interactions in monoamines have hindered their further application. Here, 1D lead‐free ferroelectric (BDA)SbBr 5 ( 1 , where BDA is 1,4‐butanediammonium) is fabricated to achieve PPE detection. Compound 1 exhibits significant symmetry breaking attributed to the order–disorder transition of organic cations and octahedral distortions. Specifically, compound 1 enables broad‐spectrum PPE detection from UV to near‐infrared (377–980 nm) and further realizes switchable pyroelectric current after polarization. More importantly, the stability of the pyroelectric current is preserved without degradation over three months, attributed to the hydrogen bonding interactions of butanediamide. Further theoretical calculations of compound 1 reveal a more negative energy of formation than its monoamine homologs (BA) 2 SbBr 5 (where BA is n‐butylammonium), which is evidence of its stability. These findings highlight 1 as a promising candidate for high‐stability and environmentally friendly PPE wide‐spectrum detection, representing a noteworthy advancement in the ferroelectric field.