Computer-aided screening of bismuth molybdates nonlinear optical crystals γ-Bi2MoO6

Abstract

Nonlinear optical (NLO) materials are key components of laser systems that extend their frequency and module laser beam. In this case, d⁰ transition metals (d⁰-TMs) and cations with stereochemically active lone pairs (SCALPs) can induce asymmetric coordination environment in crystals owing to second-order Jahn–Teller (SOJT) effects and accordingly are beneficial in enhancing NLO properties. In this work, the first-principles screening method was used to search for NLO materials in a bismuth molybdate system. Finally, γ-Bi₂MoO₆ and Bi₁₀Mo₃O₂₄ were screened and synthesized via high-temperature solid-state synthesis. γ-Bi₂MoO₆ showed a strong second harmonic generation (SHG) response (9.9 × KDP), large birefringence (0.21 at 1064 nm), and appropriate band gap (2.57 eV). This work presents systematic research on the application of bismuth molybdate systems as nonlinear optical materials and provides a reference for their further development.