Engineering an Excellent <i>β</i> ‐BaB <sub>2</sub> O <sub>4</sub> ‐Inspired UV Nonlinear Optical Material Through Secondary Building Unit Substitution
Lingli Wu, Chensheng Lin, Haotian Tian, Yan Tao, Bingxuan Li, Huixin Fan, Yujie Fan, Shunda Yang, Min Luo
Abstract
Abstract The development of nonlinear optical (NLO) crystals with tailored properties has been a long‐standing pursuit, yet remains challenging to achieve. Herein, we report the successful synthesis of a novel high‐performance UV NLO material, Li 3 [Be 3 (OH) 3 (C 3 H 2 O 4 ) 3 ]·7H 2 O (LBOC), by substituting the [B 3 O 6 ] functional building units (FBUs) in the classic β ‐BaB 2 O 4 ( β ‐BBO) with meticulously designed [Be 3 (OH) 3 (C 3 H 2 O 4 ) 3 ] 3− secondary building units (SBUs). The [Be 3 (OH) 3 (C 3 H 2 O 4 ) 3 ] 3− SBUs within LBOC preserve the ordered arrangement of the [B 3 O 6 ] FBUs found in β ‐BBO, enabling LBOC to inherit the strong second harmonic generation (SHG) response from β ‐BBO. Additionally, the increased dimensionality of the [Be 3 (OH) 3 (C 3 H 2 O 4 ) 3 ] 3− SBUs, compared to the planar [B 3 O 6 ] FBUs, leads to a reduction in optical anisotropy. Consequently, LBOC demonstrates a moderate birefringence of [email protected] nm, lower than that of β ‐BBO ([email protected] nm). Notably, bulk crystals of LBOC can be easily grown using a straightforward solution evaporation method, making it a promising candidate for UV NLO applications. This strategic design of the SBU opens new avenues for the rational development of NLO crystals with tailored properties.