Li-Free ternary sulphide Cs5Ga9S16 with excellent nonlinear optical performance similar to classic LiGaS2

The most electropositive element, Cs, was introduced into [Ga 9 S 16 ] 5− framework to acquire the noncentrosymmetric sulphide Cs 5 Ga 9 S 16 , displaying outstanding optical performance when avoided the problem of silica tube corrosiveness similar to LiGaS 2 .