Structural Modulation from Cu₃PS₄ to Cu₅Zn_0.5P₂S₈: Single-Site Aliovalent-Substitution-Driven Second-Harmonic-Generation Enhancement

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, Cu 5 Zn 0.5 P 2 S 8 , is successfully discovered, taking known Cu 3 PS 4 as the template via a single-site aliovalent-substitution strategy. It crystallizes in the orthorhombic system with noncentrosymmetric space group Pmn2 1 , and the 3D DL structure is built by corner-shared [(Cu/Zn)S 4 ], [CuS 4 ], and [PS 4 ] tetrahedra. Compared with its parent Cu 3 PS 4 , Cu 5 Zn 0.5 P 2 S 8 exhibits a good phase-matching capability and a sharply enhanced SHG effect (10Cu 3 PS 4 ) 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.

Two Nonlinear Optical Thiophosphates Cu5Hg0.5P2S8 and AgHg3PS6 Activated by Their Tetrahedra-Stacking Architecture

“…The Cu/vacancy–S bond lengths (2.273(3)–2.312(3) Å) are less than the Cu/Hg–S bond lengths (2.349(1)–2.419(2) Å), while the bond angle range (107.534(8)–113.930(6)°) of the former is larger than that of the latter (108.364(4)–112.697(9)°). Both are comparable with those of similar compounds. ,− Meanwhile, in AgHg 3 PS 6 , the lengths of the Hg–S bonds are between 2.232(2) and 2.743(4) Å, and the Ag–S bond lengths are 2.491(7) and 2.633(4) Å, consistent with those of AgHgPS 4 and AgGa 2 PS 6 …”

Rational designviadual-site aliovalent substitution leads to an outstanding IR nonlinear optical material with well-balanced comprehensive properties

“…Among them, chemical substitution is considered to be the simplest and most effective method. 10,11 On one hand, it can greatly improve the IR-NLO properties of chalcogenides, such as, Li 0.6 Ag 0.4 GaS 2 (d eff ¼ 1.1 Â AgGaS 2 ) versus LiGaS 2 (d eff ¼ 0.4 Â AgGaS 2 ), 12 Cu 5 Zn 0.5 P 2 S 8 (d eff ¼ 0.3 Â AgGaS 2 ) versus Cu 3 PS 4 (d eff ¼ 0.03 Â AgGaS 2 ), 13 and Sr 1.3 Pb 0.7 GeSe 4 (d eff ¼ 16 Â SiO 2 ) versus Pb 2 GeSe 4 (d eff ¼ 2 Â SiO 2 ). 14 On the other hand, it can realize centrosymmetric (CS)-to-NCS structure evolution in the chalcogenide system.…”

First Investigation of Nonlinear Optical Oxychalcogenide with Three‐Dimensional Anionic Framework and Special Windmill‐Like Functional Motifs†

“…[ 2 ] However, these materials encounter the disadvantages of harmful two‐photon absorption and low laser‐induced damage thresholds (LIDTs). [ 3 ] Therefore, it is necessary to explore new MIR NLO materials with balanced performances. The exploration is challenging since most discovered ones cannot achieve a good balance between large SHG intensities and high LIDTs.…”