Direct Synthesis of Ag−In−Zn−S Quantum Dot Inks for Solution-Processed Optoelectronics

Non-toxic I−III−VI quantum dots (QDs) hold strong potential for optoelectronics but are hindered by complex synthesis and post-processing requirements. Here, we demonstrate a direct synthesis of Zn-alloyed AgIn5S8 (AIZS) QDs that produces high-quality inks in N,N-dimethylformamide (DMF). The colloidal stability originates from a solvation layer comprising mainly surface-bound oxygen-coordinated In−DMF complexes. The resulting QDs exhibit strong n-type character and photoluminescence quantum yield (PLQY) of ca. 43%. Proof-of-concept quantum dot light-emitting diodes (QDLEDs) were fabricated based on this material, demonstrating the feasibility of processing functional emitting layers directly from polar inks.