Strong Second Harmonic Generation from the Tantalum Thioarsenates A₃Ta₂AsS₁₁ (A = K and Rb)

Abstract

The strongly anisotropic thioarsenates A(3)Ta(2)AsS(11) are stabilized in a polysulfide flux. All compounds contain the same parallel (1)/(infinity)[Ta(2)AsS(11)(3-)] polymeric anionic chains, but the size of the alkali-metals has a profound effect on the packing of the chains. The K(+) or Rb(+) favor noncentrosymmetric packing of the chains, whereas the larger Cs(+) favors the centrosymmetric packing. The chains feature the combination of two asymmetric units [Ta(2)S(11)] and [AsS(3)] and exhibit strong nonlinear optical (NLO) second harmonic generation (SHG) response. Polycrystalline samples exhibit is up to approximately 15 times stronger SHG than that of commercially used AgGaSe(2).

Cs2B4SiO9: A Deep‐Ultraviolet Nonlinear Optical Crystal

“…, Ta 5+ , and Mo 6+ ), [12][13][14] anionic groups with stereochemically active lone pairs (e.g., [IO 3 ] À and [TeO x ] nÀ ), [15,16] [17] which combine with diverse other functional building units to produce materials with large NLO coefficients, for example, Cd 4 BiO-(BO 3 ) 3 (6 KDP), [18] Pb 2 B 5 O 9 I (13.5 KDP), [19] and Ba 23 Ga 8 Sb 2 S 38 (22 AgGaS 2 ). [20] However, the structural units produce an unwanted effect-the UV absorption edge shifts toward the red region, making them less suitable for the deep-UV applications.…”

Synthesis, Crystal Structures, Optical Properties and Theoretical Calculations of Two Metal Chalcogenides Ba2AlSbS5 and Ba2GaBiSe5

“…With stereochemically active lone-pair electrons, the above trivalent cations exhibit a flexible coordination environment for the formation of M III 'Q n units (n = 3~6; Q = chalcogen), which offers an opportunity to affect their crystal structures and physicochemical properties [13][14][15][16][17][18][19][20][21][22][23][24]. For example, AAsQ 2 (A = Li, Na; Q = S, Se) [15] and A 3 Ta 2 AsS 11 (A = K, Rb) [13] compounds feature [AsS 3 ] 3-pyramids and show strong second harmonic generation (SHG) responses; BaBiTe 3 , AgBi 3 S 5 and A 2 Bi 8 Se 13 (A = Rb, Cs) compounds exhibit small bandgaps and have promising potential as thermoelectric materials [22][23][24]; Ba 2 GaAsSe 5 shows novel [AsGaSe 5 ] 4− anions and high visible-light-induced photocatalytic reactivity [17]. In addition, overall literature research indicates that the above M III 'Q n units can bridge other functional units to form a variety of extended structures [16].…”

Synthesis, crystal structures, and optical properties of NaCdPnS3 (Pn=As, Sb)

“…Group 15 chalcogenides are very interesting not only because of their potential application as thermoelectric materials, such as Sb 2 Te 3 [1], AgPb 18 SbTe 20 [2], Mo 3 Sb 5 Te 2 [3], and AgSb x Bi 3−x S 5 [4], and nonlinear optical materials, such as AAsQ 2 (A = Li, Na; Q = S, Se) [5,6], A 3 Ta 2 AsS 11 (A = K, Rb) [7], AZrPQ 6 (A = K, Rb, Cs; Q = S, Se) [8,9], but also because of their structural diversity [10], which arises partly from the various local coordination environments centered by group 15 elements. Unlike its heavier homologues Sb and Bi, trivalent arsenic exhibits a remarkable reluctance to adopt hypervalent coordination polyhedra in its chalcogenido anions [11,12].…”