Co-crystal LiCl•(H3C3N3O3): A Promising Solar-blind Nonlinear Optical Crystals with Giant Nonlinearity from Coplanar π-conjugated Groups

The compact and reliable all-solid-state solar-blind lasers based on nonlinear optical conversion are opening the door to new industrial applications. Herein, we proposed the cyanuric acid molecule, benefitting from its wide band gap, large optical anisotropy, and strong binding interaction from hydrogen bonds, as a superior building unit for solar-blind NLO crystals. Taking co-crystal LiCl·(H3C3N3O3) as an example, our first-principles studies predict that it has short UV transparent edge of 215 nm, strong optical anisotropy (∆n~0.28) and the largest second-order coefficient (d22=4.15 pm/V) among all solar-blind NLO crystals.