[ABa 2 Cl][Ga 4 S 8 ] (A = Rb, Cs): Wide-Spectrum Nonlinear Optical Materials Obtained by Polycation-Substitution-Induced Nonlinear Optical (NLO)-Functional Motif Ordering

• Published in: Journal of the American Chemical Society Vol. 142; no. 24; pp. 10641 - 10645
• Main Authors: Liu, Bin-Wen, Jiang, Xiao-Ming, Zeng, Hui-Yi, Guo, Guo-Cong
• Format: Journal Article
• Language: English
• Published: 17.06.2020
• Subjects: cations; cesium; gallium; potassium dihydrogen phosphate; rubidium; sulfides
• ISSN: 0002-7863; 1520-5126; 1520-5126
• DOI: 10.1021/jacs.0c04738

Noncentrosymmetry (NCS) is a prerequisite for second-order nonlinear optical (NLO) materials. In this work, a new polycation-substitution-induced centrosymmetry (CS)-to-NCS transformation strategy was applied in CS RbGaS₂, affording two novel NCS salt-inclusion chalcogenides: [ABa₂Cl][Ga₄S₈] (A = Rb, 1; Cs, 2). Remarkably, they exhibit the key merits of both Vis and IR NLO candidates, including strong phase-matchable second harmonic generation intensities (10.4–15.3 × KH₂PO₄ at 1064 nm; 0.9–1.0 × AgGaS₂ at 1910 nm), high laser-induced damage thresholds (11–12 × AgGaS₂), and a wide transparent window. Their prominent NLO performances originate from the orderly packing of T2-supertetrahedral Ga₄S₁₀ motifs resulting from the template effect of acentric polycation [ClA₂Ba₃]⁷⁺. The CS-to-NCS transformation first realized by polycation-substitution-induced NLO-functional motif ordering provides an effective approach for designing new NLO materials.