Second-Harmonic-Generation-Active Oxyhalides: CuSb₂O₃X (X = Cl, Br)

Abstract

Metal oxyhalides have attracted broad interest recently because of their diverse structures and versatile properties. Here, two oxyhalides, CuSb 2 O 3 Cl (1) and CuSb 2 O 3 Br (2), were studied by focusing on their nonlinear-optical properties. They are crystallized in the noncentrosymmetric monoclinic Cc structure, and the layered structures could be derived from a 1:1 combination of CuX-(X = Cl, Br) and Sb 2 O 3 -type slabs. Their energy gaps were determined to be 2.76 and 2.64 eV. The second-harmonicgeneration (SHG) test suggests that they are nonlinear-optical-active, and the effects are ascribed to the contribution of CuX 3 O units. Meanwhile, the SbO 3 units' arrangement has a small contribution to the SHG effects. This work is the pioneer SHG investigation of the M I −M III −O−X (M I = Cu, Ag; M III = trivalent As, Sb, Bi; X = halogen) family.

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

“…Oxybromides are compounds constructed by O 2– and Br – as anions. The chemically distinct O 2– (ionic size: 126 pm; electronegativity: 3.4) and Br – (ionic size: 182 pm; electronegativity: 3.0) made most oxybromides as ordered heteroanionic compounds, − which results in pliable structural chemistry and fruitful physical phenomena, such as nonlinear optical properties. − In this work, we report the crystal structure and growth, electronic structures, chemical bonding pictures, linear and NLO properties, and photoluminescent (PL) properties of LaBrMoO 4 and LaBrWO 4 . LaBrMoO 4 was structurally characterized without any property measurements.…”

Sb5O7I: Exploration of Ternary Antimony-Based Oxyhalide as a Nonlinear-Optical Material

“…Among them, the P6 3 and P62c structures have different crystallographically independent atomic species in the asymmetric units, in which the P6 The Kubelka−Munk transformation and Tauc method were introduced to estimate the energy gap of Sb 5 O 7 I. The result suggests a direct energy gap of 3.22 eV, compatible with the crystals' transparent color (Figure 3a), which is far higher than the energy gaps of other metal oxyhalides, like CuSb 2 O 3 Cl (2.74 eV), 26 CuSb 2 O 3 Cl (2.64 eV), 26 Sb 3 O 4 I (2.16 eV), 48 Sb 8 O 11 I 2 (2.74 eV), 48 BiOI (1.83 eV), 33 and Bi 4 O 5 I 2 (2.39 eV). 33 To our knowledge, Sb 5 O 7 I has the largest energy gap of all reported ternary oxyiodides (Table S6).…”

“…Recently, NLO materials containing mixed anions have been considered as promising candidates with optimized comprehensive properties. − Notably, metal oxyhalides, a branch of enormously relevant mixed-anion compounds that have diverse structural features and physical properties, have received rapidly increasing interest. − Metal oxyhalides Bi 7 F 11 O 5 , KWO 3 F, CdPb 2 Te 3 O 8 Cl 2 , Pb 17 O 8 Cl 18 , Pb 13 O 6 Cl 4 Br 10 , and CuSb 2 O 3 X (X = Cl, Br) are reported to exhibit second-harmonic-generation (SHG) responses. It can be noted that most of these oxyhalides are fluorides, chlorides, and bromides, while iodides are very rare because of their synthetic difficulties.…”

“…To further understand the structure–NLO performance relationship, the dipole moment (DM) of the SbO 3 groups within a single cell is calculated to be 54.7 D. As shown in Figure d, the DM vectors of the SbO 3 groups are primarily oppositely directed, leading to a small net DM. , To analyze the effect of Sb 3+ -ion lone pairs, an electron localization function (ELF) calculation was performed. Figure e clearly displays a slightly asymmetric electron distribution on the Sb 3+ cations, namely, the stereochemically active lone pairs.…”

Hg3O2(NO3)F: a mercury nitrate oxyfluoride with an unprecedented [(Hg3O2F)+]∞cationic framework and excellent optical anisotropy

“…The combination of two or more kinds of anion groups to design compounds with interesting structure types is a favorable and fruitful route. 1–32 These new crystals may synergize the properties of multiple anions and can be potential candidates in some application fields including birefringence, nonlinear optics, fluorescence, and catalysis. Based on the structure performance relationship, many research systems focusing on optical performance have been developed in recent years.…”