Aluminoborates as Nonlinear Optical Materials

Abstract Ultraviolet (UV) and Deep‐UV (DUV, λ <200 nm) nonlinear optical (NLO) materials play a significant role to convert the wavelength of laser for producing UV/DUV coherent light in the laser industry. The Al [Ne]3 s 2 3 p 1 atom with empty d orbitals can form s p 3 , sp 3 d , and sp 3 d 2 hybrid orbitals when bonding with O/F atoms, which leads to the construction of [AlO m F n ] ( m + n =4, 5, 6) units. Therein, aluminoborates have received intensive attention due to the effective structural and functional adjustment effects of the diverse Al−O/F units. Accordingly, numerous aluminoborates as candidates for the next generation of UV/DUV NLO materials were discovered. In this review, recently discovered aluminoborates are overviewed and analyzed, including their syntheses, crystal structure features, and second‐order NLO performances. We aim to provide the latest progress and outlook on the crystal chemistry of aluminoborates and boost the finding of the next NLO candidates with high performances.