LiZn(OH)CO3: A Deep‐Ultraviolet Nonlinear Optical Hydroxycarbonate Designed from a Diamond‐like Structure

Abstract Deep‐ultraviolet (DUV) nonlinear optical (NLO) crystals are vital to the development of science and state‐of‐the‐art technologies, but the exploration of these important optoelectronic materials is hindered by the contradiction between NLO effect and energy band gap as well as the sensitivity of DUV phase‐matching to optical birefringence. Here, in order to achieve a well balanced DUV NLO performance, we chose the diamond‐like structure as the prototype template for the material design and synthesized the first DUV NLO hydroxycarbonate crystal, LiZn(OH)CO 3 . This compound simultaneously has a wide band gap (>6.53 eV), a strong second harmonic generation response (ca. 3.2×KDP), and a large birefringence (0.147 at 1064 nm) with the shortest DUV phase‐matching capability ( λ PM <190 nm) among all reported NLO carbonates. Moreover, the structure–property relationships in LiZn(OH)CO 3 are analyzed by first‐principles calculations. This work presents an effective design strategy to push the NLO performance of hydroxycarbonates into the DUV region.