The compatibly large nonlinear optical effect and high laser-induced damage threshold in a thiophosphate CsInP ₂ S ₇ constructed with [P ₂ S ₇ ] ^4- and [InS 6 ] ^9-

It is challenging to cooperatively improve the nonlinear optical (NLO) efficiency and the laser-induced damage threshold (LIDT). This work reports a novel IR NLO materials CsInP 2 S 7 (CIPS) designed by combination the strategies of alkali metals substitution and microscopic NLO units PS 4 introduction based on AgGaS 2 . CIPS was composed of strongly distorted [InS 6 ] 9- octahedra and [P 2 S 7 ] 4- dimers constructed by corner-sharing [PS 4 ] 3- , which increase the NLO efficiency and decrease thermal expansion anisotropy simultaneously. Compared with AgGaS 2 , CIPS exhibited strong phase matchable NLO response ca. 1.1 x AGS@2.1 mu m, high LIDT ca. 20.8 x AgGaS 2 , and IR transparency up to 15.3 mu m. Structural analysis and theoretical investigation confirmed that large SHG effect and ultrahigh LIDT of CIPS originated from the synergistic contribution of [InS 6 ] 9- octahedra and [P 2 S 7 ] 4- dimers. These results indicate that CIPS is a promising NLO candidate in the mid-IR region, and this study provides a new approach for developing potential NLO-LIDT compatible materials. (c) 2023 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.