The first salicylaldehyde Schiff base organic–inorganic hybrid lead iodide perovskite ferroelectric

A salicylaldehyde Schiff base hybrid lead iodide perovskite [SAPD]PbI3 (SAPD = 1-((2-hydroxybenzylidene)amino)pyridin-1-ium) was found to show a robust nonlinear optical response and large spontaneous polarization. We expect this work to inspire researchers to investigate the optical control of ferroelectricity in hybrid perovskites.