Breaking the SHG-stability trade-off in UV nonlinear optical materials by polar-layer-dense-locking

strong Cd-O coordination bonds and dense interlayer packing, imparting exceptional structural stability. Cd(imc) exhibits a giant SHG response (10.0 × KDP), ultrahigh thermal stability (up to 470 °C), and remarkable water resistance (retains crystallinity for >180 days in water at room temperature and >30 days at 100 °C), alongside a wide bandgap (4.28 eV). It also exhibits good phase-matchability, making it a practical candidate for UV frequency conversion. This "polar-layer-dense-locking" paradigm establishes a synergistic mechanism to decouple the SHG-stability constraints in UV NLO materials.