Relaxor-like ferroelectric response and achiral-chiral switching in an amorphous molecular solid.

Organic ferroelectrics offer a molecular platform for integrating polarization dynamics with molecular design, photoresponsiveness and chiroptical functions, including light-triggered achiral-to-chiral transitions, yet these responses remain strongly shaped by crystalline packing in the solid state. Here, we vitrify a salicylideneaniline derivative that undergoes UV-triggered achiral-to-chiral conversion and show that structural disorder enables coupled chiroptical and ferroelectric responses in an amorphous molecular solid. The vitrified state loses long-range order while retaining spatially heterogeneous local polar responses, giving a coercive field of ~5.7 kV cm⁻¹ and a maximum switchable polarization of ~26 μC cm⁻². It also exhibits over an order of magnitude faster recovery from the chiral photoactivated state than the crystalline counterpart. Moreover, circularly polarized light produces helicity-dependent dielectric and thermal responses with mirror-symmetric behavior between the (S)- and (R)-enantiomers. These results connect photoinduced symmetry switching with relaxor-like dipolar dynamics in a single-component amorphous molecular ferroelectric.