One-Dimensional Double Chains in Sodium-Based Quaternary Chalcogenides Displaying Intriguing Red Emission and Large Optical Anisotropy

Optimizing the Nonlinear Optical Performance of an A-N-M-Q (A: Alkali Metal; N: d10 Metal; M: Main Group Metal; Q: Chalcogen) System

Exploring new infrared nonlinear optical (IR NLO) materials with superior overall properties is scientifically and technically important. However, large second-order harmonic generation (SHG) efficiencies and high laser-induced damage thresholds (LIDT) are incompatible, which makes realizing this goal a challenge. The IR NLO performance of an A-N^IIB-M^IIIA-Q (Q: chalcogen) system was optimized by simultaneously modulating A/(M + N) and M/N ratios (A: alkali metal; N, M: tetra-coordinated metals), and SHG-LIDT balance was achieved. Three new sulfides, KCd₃Ga₅S₁₁ (1), RbCd₄Ga₃S₉ (2), and Cs₂Cd₂Ga₈S₁₅ (3), containing the same CdS₄ and GaS₄ but with different A/(Ga + Cd) and Ga/Cd ratios were obtained. Among these compounds, compound 3 exhibits both the largest SHG efficiency (0.5 × AgGaS₂) and LIDT (35 × AgGaS₂), which can be ascribed to the Ga/Cd modulation for enhancing the NLO functional motif distortions and SHG efficiency as well as the A/(Ga + Cd) modulation for enlarging the band gap and LIDT. Remarkably, compound 3 is the first phase-matchable IR NLO material in the A-N^IIB-M^IIIA-Q family. This article proposes a novel avenue to explore infrared nonlinear materials with superior comprehensive properties by modulating the A/(M + N) and M/N ratios.

CsCu3SbS4: rational design of a two-dimensional layered material with giant birefringence derived from Cu3SbS4

By introducing Cs into known Cu3SbS4, we successfully obtained a novel thioantimonate, quaternary CsCu3SbS4 with an unprecedented 2D layered structure, which exhibits a giant birefringence (0.232 at 549 nm).

Cs3CuAs4Q8 (Q = S, Se): unique two-dimensional layered inorganic thioarsenates with the lowest Cu-to-As ratio and remarkable photocurrent responses

Inorganic chalcogenides containing cations with lone-pair electrons have attracted considerable attention because of their potential applications in photocatalysis. In this research, two new copper thioarsenates with the lowest Cu-to-As ratio in the quaternary X/Cu/As/Q (X = inorganic cations; Q = chalcogen) system, namely Cs₃CuAs₄Q₈ (Q = S, Se), were obtained by a simple surfactant-thermal method at a low temperature. These two isostructural compounds belong to the monoclinic space group C2/c (no. 15) and are composed charge-balanced Cs⁺ cations and two-dimensional anionic [CuAs₄Q₈]^3- layers. Notably, photo-electrochemical measurements indicate that Cs₃CuAs₄Q₈ possesses a remarkable photocurrent response under simulated solar-light illumination. Further theoretical studies were performed to gain insights into the relationships between electronic structure and optical properties.

Cs2ZnSn3S8: A Sulfide Compound Realizes a Large Birefringence by Modulating the Dimensional Structure

Birefringence, an important optical performance parameter for optoelectronic functional materials, is mainly influenced by the types of anion groups and their spatial arrangement. Inspired by the relationship between the structure and properties of chalcogenides, combined with the dimensional transformation, we successfully synthesized a sulfide compound (Cs₂ZnSn₃S₈) with a two-dimensional layered structure and a large birefringence. The experimental results showed that, compared with Rb₁₀Zn₄Sn₄S₁₇, Cs₂ZnSn₃S₈ achieved the structural transition from a zero-dimensional arrangement to a two-dimensional lamellar arrangement and achieved a breakthrough of birefringence from 0 to 0.12, which was determined by both experiments and first-principles calculations. These findings demonstrated that Cs₂ZnSn₃S₈ was a potential birefringent material and provided instructions for the study of the synthesis of birefringent materials.

N, Baiyin M. Synthesis, crystal structure, photocatalysis, photocurrent response: one-dimensional K2HgSnSe4 and three-dimensional Na6Cu8Sn3Se13

Two novel selenidostannates were solvothermally synthesized and compound 2 displays a unique 3-D open frame structure.

Coordinated regulation on critical physiochemical performances activated from mixed tetrahedral anionic ligands in new series of Sr6A4M4S16 (A = Ag, Cu; M = Ge, Sn) nonlinear optical materials

Coordinated regulation on physiochemical performances activated from mixed anionic ligands in a new series of IR NLO materials was systematically investigated.