A Rare‐Earth Selenite with Unexpectedly Well‐Balanced Ultraviolet Nonlinear Optical Functionality, Sc(HSeO3)3

Abstract

AbstractEstablishing high performance ultraviolet (UV) nonlinear optical (NLO) selenite crystals with well‐balanced properties is very challenging attributable to their strong absorption for UV light. Here a rare‐earth selenite, Sc(HSeO3)3, with excellent UV NLO properties is introduced. Sc(HSeO3)3 crystallizing in the polar NCS space group, Cc, features a 3D archetiture built up by interconnected ScO6 octahedra and HSeO3 groups. The crystal exhibits remarkably well‐balanced UV‐NLO functionality, namely, the shortest absorption edge (214 nm) among NLO‐active selenites, wide bandgap (5.28 eV), large phase‐matchable SHG response (5 × KDP), and sufficiently large birefringence (cal. 0.105 @1064 nm). Detailed DFT calculations have been performed to elucidate the structure–property relationships. This work provides a new example of discovering novel UV NLO selenite materials.