Non‐centrosymmetric Selenides AZn₄In₅Se₁₂ (A=Rb, Cs): Synthesis, Characterization and Nonlinear Optical Properties

Abstract

Two new non-centrosymmetric polar quaternary selenides, namely, RbZn In Se and CsZn In Se , have been synthesized and structurally characterized. They exhibit a 3D diamond-like framework (DLF) consisting of corner-shared MSe (M=Zn/In) tetrahedra, in which the A ions are located. Both compounds are thermally stable up to 1300 K and exhibit large transmittance in the infrared region (0.65-25 μm) with measured optical band gaps of 2.06 eV for RbZn In Se and 2.11 eV for CsZn In Se . Inspiringly, they exhibit a good balance between strong second harmonic generation (SHG) efficiency (3.9 and 3.5×AgGaS ) and high laser-induced damage thresholds (13.0×AgGaS ). Theoretical calculations based on density functional theory (DFT) methods confirm that such strong SHG responses originate from the 3D DLF structure.

Coexistence of Strong Second Harmonic Generation Response and Wide Band Gap in AZn4Ga5S12 (A=K, Rb, Cs) with 3D Diamond‐like Frameworks

“…[29][30][31][32][33] The structural evolution, as depicted in Figure2,o ft he title compounds AZn 4 Ga 5 S 12 (space group: R3) is derived from the ternary AgGaS 2 (space group: I4 2d)p arent [35] by replacing the (6Ag + 6Ga) cations with the (4Zn + 5Ga) cations and with A + cations maintaining the charge balance. [29][30][31][32][33] The structural evolution, as depicted in Figure2,o ft he title compounds AZn 4 Ga 5 S 12 (space group: R3) is derived from the ternary AgGaS 2 (space group: I4 2d)p arent [35] by replacing the (6Ag + 6Ga) cations with the (4Zn + 5Ga) cations and with A + cations maintaining the charge balance.…”

“…[12] Surprisingly,s uch av alue is even greater than some notable IR halideso ro xides, for example, Cs 2 HgCl 2 I 2 (3.15 eV), [36] Pb 17 O 8 Cl 17 (3.44 eV), [37] Pb 2 B 5 O 9 I( 3.10 eV), [38] and Li 2 Ti(IO 3 ) 6 (3.00 eV). [29][30][31][32][33] The powder SHG properties were estimated on polycrystalline samples by using a2 050 nm Q-switch laser based on the Kurtz and Perry method. [29][30][31][32][33] The powder SHG properties were estimated on polycrystalline samples by using a2 050 nm Q-switch laser based on the Kurtz and Perry method.…”

“…Systematic results suggest that diverse band gaps are based on the substitutional flexibility in the AX II 4 X III 5 Q 12 family [29][30][31][32][33] (Figure 7) and somewhat predictably:1 )they have aw ide band adjustment range, from the minimum value (1.42 eV for CsCd 4 In 5 Te 12 )t ot he maximum value (3.65 eV forA Zn 4 Ga 5 S 12 ); 2) the chalcogenide Qp lays ak ey effect in affectingt he E g and this can be observed in the CsCd 4 Ga 5 Q 12 (Q = S, Se, Te) series, [29,30,32] whichh ave values of 3.09, 2.21, and 1.67 eV for the sulfide, selenide, and telluride, respectively;3 )the divalent (X II )i on has less of ac ontribution on affecting the E g ,a nd replacing X II in CsX II 4 In 5 Te 12 resultsi nadecrease of~0.1-0.2 eV; [31] 4) The alkali metal (A) almost hasn oa ffect on the E g . Whereas, the role of trivalent (X III )i sm ore noticeable, the lager atomic number would result in as maller bang gap, for example, E g (CMIT) < E g (CMGT)a nd E g (CCIT) < E g (CCGT).…”

“…[29][30][31][32][33]44] Single-crystal X-ray diffraction (XRD) [29][30][31][32][33]44] Single-crystal X-ray diffraction (XRD)…”

“…[29][30][31][32][33] Previous studies suggestt hat that ACd 4 Ga 5 S 12 exhibits not only very strong powder SHG ( % 10 AGS), but also ar elatively large E g ( % 3.0 eV). Recently,anewt ype of 3D DLF frameworkm aterial with the formula AX II 4 X III 5 Q 12 [A = alkali metal (K, Rb andC s);X II = transition metal (Mn, Zn, and Cd);X III = group 13 metal (Ga and In);Q= chalcogenide (S, Se, and Te )] attracted our attention and as ystematici nvestigation of this system was carried out.…”