Regulating Guanidinium-Based Hybrid Materials for Ultraviolet Nonlinear Optical Applications by Hybrid Strength and Hybrid Pattern.

Combining the advantages of organic and inorganic motifs, organic-inorganic hybrid materials can exhibit excellent nonlinear optical (NLO) performance. In this article, through systematic first-principles modeling and simulations, we investigated the NLO performance of an organic planar conjugated guanidinium cation [C(NH2)3+, guanidinium (GU)] and its hybrid materials with various inorganic anionic groups. It is demonstrated that GU-based hybrid materials are excellent candidates for ultraviolet (UV) NLO conversion, especially for the important 266 nm laser output in the solar-blind region, because of their wide UV transparency, strong second harmonic generation (SHG) effect, and large optical birefringence. Moreover, the UV NLO performance can be regulated by the hybrid strength and/or hybrid pattern between the GU cations and different kinds of inorganic anionic groups, which would help to explore new UV NLO materials in the hybrid material system.