Ba<sub>6</sub>Zn<sub>7</sub>Ga<sub>2</sub>S<sub>16</sub>: A Wide Band Gap Sulfide with Phase-Matchable Infrared NLO Properties Yan-Yan Li Peng-Fei Liu Li-Ming Wu 10.1021/acs.chemmater.7b01321.s001 https://acs.figshare.com/articles/journal_contribution/Ba_sub_6_sub_Zn_sub_7_sub_Ga_sub_2_sub_S_sub_16_sub_A_Wide_Band_Gap_Sulfide_with_Phase-Matchable_Infrared_NLO_Properties/5099002 High-performance infrared (IR) nonlinear optical (NLO) materials with large laser damage thresholds (LDTs) are urgently needed because the current commercially available AgGaS<sub>2</sub>, AgGaSe<sub>2</sub>, and ZnGeP<sub>2</sub> suffer their very low LDTs which shorten significantly their service lifetimes. Here, a novel sulfide, Ba<sub>6</sub>Zn<sub>7</sub>Ga<sub>2</sub>S<sub>16</sub> with a very wide band gap of 3.5 eV, has been discovered. This compound crystallizes in the chiral trigonal <i>R</i>3 space group with a novel 3D framework that is constructed by ZnS<sub>4</sub> tetrahedra, Zn<sub>3</sub>GaS<sub>10</sub> supertetrahedra (a T2-type), and Zn<sub>3</sub>GaS<sub>10</sub> quadri-tetrahedral clusters via vertex-sharing. Such a novel structure exhibits desirable features which suggest a promising NLO material: phase-matchability (PM), good NLO efficiency (about half that of benchmark AgGaS<sub>2</sub>), and the highest LDT among PM chalcogenides (28 times that of benchmark AgGaS<sub>2</sub>). In addition, the density functional theory (DFT) calculations confirm its PM behavior and reveal that the second harmonic generation (SHG) origin is mainly ascribed to the transition process from S-3p to Ga-4p, Zn-3p, Zn-3d, and Ba-5d states; the calculated <i>d</i><sub>11</sub> coefficient of 6.1 pm/V agrees well with experimental values. 2017-05-31 00:00:00 benchmark AgGaS 2 band gap R 3 space group AgGaSe 2 T 2-type Wide Band Gap Sulfide AgGaS 2 11 coefficient S -3p LDT Zn 3 GaS 10 supertetrahedra compound crystallizes PM behavior SHG NLO Properties High-performance Ba 6 Zn 7 Ga 2 S 16 laser damage thresholds ZnGeP 2 DFT novel sulfide transition process novel structure exhibits novel 3 D framework service lifetimes Ga -4p Zn -3p Zn -3d NLO efficiency Zn 3 GaS 10 quadri-tetrahedral clusters ZnS 4 tetrahedra IR 3.5 eV Ba -5d states NLO material