Structural Modulation from Cu<sub>3</sub>PS<sub>4</sub> to Cu<sub>5</sub>Zn<sub>0.5</sub>P<sub>2</sub>S<sub>8</sub>: Single-Site Aliovalent-Substitution-Driven Second-Harmonic-Generation Enhancement
Bang-Jun Song, Zuju Ma, Bingxuan Li, Xintao Wu, Hua Lin, Qi‐Long Zhu
Abstract
Diamond-like (DL) chalcophosphates, which possess the merits of impressive second-harmonic-generation (SHG) responses, strong laser-induced damage thresholds, and low melting points, are highly desirable for IR nonlinear-optical (NLO) applications. Herein, a new quaternary DL chalcophosphate, Cu5Zn0.5P2S8, is successfully discovered, taking known Cu3PS4 as the template via a single-site aliovalent-substitution strategy. It crystallizes in the orthorhombic system with noncentrosymmetric space group Pmn21, and the 3D DL structure is built by corner-shared [(Cu/Zn)S4], [CuS4], and [PS4] tetrahedra. Compared with its parent Cu3PS4, Cu5Zn0.5P2S8 exhibits a good phase-matching capability and a sharply enhanced SHG effect (10Cu3PS4) benefiting from partial Zn substitution. Moreover, the structure–performance relationships have been illustrated by means of theoretical investigations. Such an aliovalent-substitution strategy based on known DL semiconductors might be widely applied for the discovery of high-performance IR NLO crystals.