posted on 2021-07-22, 15:03authored byChao Wu, Lin Lin, Tianhui Wu, Wenyan Dan, Zhipeng Huang, Chi Zhang
The
exploration of noncentrosymmetric chalcogenides is important
for discovering second-oeder nonlinear optical (NLO) materials. We
herein report two new gallium thioantimonates, (NH4)2.7Cs1.3Ga4SbS9S0.3O0.7H (GaSbS-I) and Cs4Ga4SbS9S0.3O0.7H (GaSbS-II), which have been
successfully synthesized by facile solvothermal methods. GaSbS-I and
GaSbS-II are isostructural, and they exhibit a three-dimensional open
framework constructed by [Ga4S9Q] units and
[SbS3] units. Both two compounds are second harmonic generation
(SHG) active with powder SHG efficiencies of 1.2 and 1.4 times that
of the benchmark KH2PO4 (KDP) in a non-phase-matching
behavior at 1064 nm. The calculated band gaps for GaSbS-I and GaSbS-II
are 2.08 and 2.36 eV, respectively, consistent with the experimental
values of 2.60 and 2.95 eV. The crystal structures and their optical
performance relationship have been clarified by theoretical investigations
based on the DFT method.