NaZnCO3(OH): A High-Performance Carbonate Ultraviolet Nonlinear Optical Crystal Derived from KBe2BO3F2

Currently, to obtain new ultraviolet (UV) nonlinear optical (NLO) materials with large second-harmonic generation (SHG) response and short SHG phase-matching cutoff wavelength (lambda(PM)) is still very challenging. Herein, through evolving the KBe2BO3F2 (KBBF) structure to a carbonate system, a novel hydroxycarbonate UV NLO crystal, NaZnCO3(OH), was successfully synthesized. It not only possessed the typical structural characteristics of KBBF but also enhanced the bonding force between functional layers. Remarkably, in this crystal, the rare coexistence of a very large SHG response of 5.2 x KH2PO4 (KDP, @1064 nm) and short type-I SHG lambda(PM) of 201 nm had been achieved, indicating that it was a promising UV NLO crystal. This work showed the great significance of KBBF structure evolution and provided new opportunity to design UV NLO materials with good performance.