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Solution-processed semiconducting main-group chalcogenides (MMCs) have attracted increasing research interest for next-generation device technologies owing to their unique nanostructures and superior properties. To achieve the full potential of MMCs, the development of highly universal, scalable, and sustainable synthesis and processing methods of chalcogenide particles is thus becoming progressively more important. Here we studied scalable factors for the synthesis of two-dimensional (2D) V–VI chalcogenide nanoplates (M 2 Q 3  : M = Sb, Bi; Q = Se, Te) and systematically investigated their colloidal behaviour and chemical stability. Based on a solvent engineering technique, we demonstrated scale-up syntheses of MMCs up to a 900% increase of batch size compared with conventional hydrazine-based gram-level syntheses, and such a scalable approach is highly applicable to various binary and ternary MMCs. Furthermore, we studied the stability of printable chalcogenide nanoparticle inks with several formulation factors including solvents, additives, and pH values, resulting in inks with high chemical stability (>4 months). As a proof of concept, we applied our solution-processed chalcogenide particles to multiple additive manufacturing methods, confirming the high printability and processability of MMC inks. The ability to combine the top-down designing freedom of additive manufacturing with bottom-up scalable synthesis of chalcogenide particles promises great opportunities for large-scale design and manufacturing of chalcogenide-based functional devices for broad application. 

Abstract The dearth of suitable materials significantly restricts the practical development of infrared (IR) laser systems with highly efficient and broadband tuning. Recently, γ‐NaAsSe₂is reported, and it exhibits a large nonlinear second‐harmonic generation (SHG) coefficient of 590 pm V⁻¹at 2 µm. However, the crystal growth of γ‐NaAsSe₂is challenging because it undergoes a phase transition to centrosymmetric δ‐NaAsSe₂. Herein, the stabilization of non‐centrosymmetric γ‐NaAsSe₂by doping the As site with Sb, which results in γ‐NaAs_0.95Sb_0.05Se₂is reported. The congruent melting behavior is confirmed by differential thermal analysis with a melting temperature of 450 °C and crystallization temperature of 415 °C. Single crystals with dimensions of 3 mm × 2 mm are successfully obtained via zone refining and the Bridgman method. The purification of the material plays a significant role in crystal growth and results in a bandgap of 1.78 eV and thermal conductivity of 0.79 Wm⁻¹K⁻¹. The single‐crystal SHG coefficient of γ‐NaAs_0.95Sb_0.05Se₂exhibits an enormous value of |d₁₁| = 648 ± 74 pm V⁻¹, which is comparable to that of γ‐NaAsSe₂and ≈20× larger than that of AgGaSe₂. The bandgap of γ‐NaAs_0.95Sb_0.05Se₂(1.78 eV) is similar to that of AgGaSe₂, thus rendering it highly attractive as a high‐performing nonlinear optical material.