In:
Journal of Materials Chemistry C, Royal Society of Chemistry (RSC), Vol. 10, No. 9 ( 2022), p. 3300-3306
Abstract:
Noncentrosymmetric (NCS) structure is the precondition for second-order nonlinear optical (NLO) materials. In this work, we present a new strategy for constructing NCS structures, whereby mixed alkali metals make a new NCS chalcogenide, (Na 3 Rb)Hg 2 Ge 2 S 8 , based on the centrosymmetric (CS) Rb 4 Hg 2 Ge 2 S 8 . (Na 3 Rb)Hg 2 Ge 2 S 8 crystallizes in the polar space group of Pca 2 1 , and adopts a filled cristobalite-type structure with a {[HgGeS 4 ] 2− } ∞ framework formed by the alternating connection of [HgS 4 ] and [GeS 4 ] tetrahedra via corner-sharing and with the mixed alkali metal cations in the cavities of the framework. Structural analysis and theoretical calculations suggest that the ordered and alternating arrangement of NLO-active chromophores, [HgS 4 ] and [GeS 4 ] tetrahedra, induced by partial substitution of alkali metals plays an important role in the enhanced second harmonic generation activity. As such, (Na 3 Rb)Hg 2 Ge 2 S 8 exhibits strong second harmonic generation response of 1.4 × AgGaS 2 at 2090 nm, wide band gap of 2.76 eV and low melting point of 444 °C. Therefore, this strategy of mixed alkali metals may shed light on structural modification from CS to NCS for new NLO materials.
Type of Medium:
Online Resource
ISSN:
2050-7526
,
2050-7534
Language:
English
Publisher:
Royal Society of Chemistry (RSC)
Publication Date:
2022
detail.hit.zdb_id:
2702245-6
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