Synthesis, Crystal and Electronic Structures, and Nonlinear Optical Properties of Y₄Si₃S₁₂

Abstract

A new acentric sulfide Y 4 Si 3 S 12 was grown by a high temperature vapor transport reaction. The crystal structure of Y 4 Si 3 S 12 was determined by single crystal X-ray diffraction. Y 4 Si 3 S 12 is isostructural to La 4 Ge 3 S 12 . The three dimensional structure of Y 4 Si 3 S 12 is constructed by [Y1S 7 ] augmented triangular prisms, [Y2S 6 ] triangular prisms and [SiS 4 ] tetrahedra through sharing vertices and edges. Y 4 Si 3 S 12 is revealed as an indirect bandgap semiconductor with a calculated bandgap of 2.1 eV, which is close to 2.5(1) eV experimentally measured by UV-Vis. The YÀ S interactions and SiÀ S interactions are predicated to be strong ionic bonds and covalent bonds, respectively, by electron localization function coupled with crystal orbital Hamilton population calculations. Y 4 Si 3 S 12 is verified by DFT calculations to have moderate birefringence, with incident 1900 nm laser, Δn = 0.09. DFT calculations also predicted that Y 4 Si 3 S 12 possesses moderate second harmonic generation response with χ 111 = 15.03 pm/V. The nonlinear optical properties of Y 4 Si 3 S 12 are mainly contributed by YÀ S interactions revealed by DFT calculations.

Heteroanionic LaBrVIO4 (VI = Mo, W): Excellence in Both Nonlinear Optical Properties and Photoluminescent Properties

“…The W2–O7–W2 bond angles are 158.1(4)° and 158.7(4)° for LaBrWO 4 and (La 0.9 Dy 0.1 )­BrWO 4 , respectively. The importance of the distortion degree of structure motifs contributing to NLO materials has been reported in many works. − ,− The 1D [VIO 5 ] VI = Mo,W strands are similar to many well-known lambda (Λ)-shaped building units in many NLO optical materials, such as K 5 Nb 3 O 3 F 14 ·H 2 O, K 10 (Nb 2 O 2 F 9 ) 3 F, K 10 (Nb 2 O 2 F 9 ) 3 I 2 , β-Ba 2 [VO 2 F 2 (IO 3 ) 2 ]­IO 3 , K 5 (W 3 O 9 F 4 ) (IO 3 ), Sn 2 B 5 O 9 Br, etc., where the distortion of Λ-shaped building units plays a critical role in dominating NLO properties. A summary of compounds constituting Λ-shaped building units is tabulated in Table S7. ,,− LaBrWO 4 can also host more rare earth elements than LaBrMoO 4 , which exhibits intriguing PL properties.…”

“…The small amounts of dysprosium doping also dramatically enhance the SHG response of (La 0.9 Dy 0.1 )­BrWO 4 . Understanding how to enhance SHG in NLO materials is critical for pushing this field forward. − In addition to the SHG response, LaBrWO 4 also possesses better PL properties than LaBrMoO 4 (vide infra). Our further analysis confirms that the distorted 1D [VIO 5 ] VI = Mo,W strands play a critical role in determining the optical properties of LaBrVIO 4 (VI = Mo and W) (vide infra).…”

Synthesis, Crystal and Electronic Structures, Nonlinear Optical Properties, and Magnetic Properties of Two Thiophosphates: KInP2S7 and KCrP2S7

“…Hence, a future bandgap engineering possibility is to modify the [PS 4 ] tetrahedron, in example, by introducing As atoms or Sb atoms to replace P atoms so to suppress the bandgap and enhance SHG response [56]. To further understand the optical properties of KInP 2 P 7 , a DFT calculation is undergoing [57][58][59].…”

Synthesis, crystal and electronic structures, linear and nonlinear optical properties, and photocurrent response of oxyhalides CeHaVIO4 (Ha = Cl, Br; VI = Mo, W)

“…Balancing these properties to satisfy these criteria is not a simple task due to the fact that many of these parameters are intrinsically correlated. 17–29 For example, in general, a material with a large bandgap should have a high LDT, but the SHG coefficients would be expected to be low. Inversely, small bandgap materials are more likely to have large SHG coefficients, but with the price of sacrificing the LDT.…”