SbO(OH)2(IO3): The First Polar Sb5+-Iodate with a Strong Second-Harmonic Generation Response and a Wide Bandgap

Widening the bandgaps while maintaining a strong second harmonic generation response has always been a research hotspot in the field of nonlinear optical iodate materials. A strategy involving covalent bonding is proposed that leverages the high valent later main group cation to construct iodates with predominantly covalent interactions. By using BiO(IO3) as a template, the first Sb5+-containing polar iodate, SbO(OH)(2)(IO3) is successfully isolated. The introduction of the two hydroxide anions led to the reduction of layered BiO(IO3) into 1D SbO(OH)(2)(IO3) in which two corner-sharing SbO4(OH)(2) octahedra are further bridged by an iodate group. The covalently bonded [SbO(OH)(2)](+) chains and the optimal packing fashion of the asymmetric IO3- groups generate a very strong second harmonic generation signal of 14 times that of KH2PO4. Furthermore, SbO(OH)(2)(IO3) exhibits a wide bandgap of 4.14 eV and a high laser induced damage threshold [27.9 x AgGaS2, 0.2 x KH2PO4 (10 ns, 10 Hz)].