Rational design of a new chalcogenide with good infrared nonlinear optical performance: SrZnSnS4

Abstract

A new quaternary sulfide SrZnSnS₄, containing “nonlinear optical (NLO) active groups” [ZnS₄]⁶⁻ and [SnS₄]⁴⁻ has been designed and synthesized with the traditional high-temperature solid-state reaction method by introducing Zn and Sn after considering the cost of raw materials. As a result, the title compound has a large energy gap of 3.37 eV using the upper tangent method. In addition, the second harmonic generation (SHG) measurements indicate that it can achieve phase-matching behavior. Meanwhile, SrZnSnS₄ possesses a second harmonic generation response approximately equivalent to that of LiGaS₂. Theoretical calculations show that the results are in agreement with the experimental manifestation, demonstrating that the title compound is a potential IR NLO material reaching a good balance between the energy gap and SHG effect.