100-Fold Scaling-Up, Gram-Level and Direct Ambient Synthesis of Perovskite Quantum Dots with High Batch Consistency.

Perovskite quantum dots (PQDs) show promising potential in the optoelectronic field, but their commercial application is limited by the scalability in laboratory scale and complicated synthesis in an inert atmosphere, especially in I-based red-emission PQDs. The PQDs are disturbed by the performance decrease in the scalable synthesis caused by the trap states from weakly-bonded ligand loss and uneven nucleation/growth from the complicated injection process. Here, a 100-fold scalable (800 mL) and gram-level (2.19 g) synthesis of CsPbI pure-red PQDs is achieved in ambient air. This is realized by a strongly-coordinated dual-ligand strategy with phosphorus-oxygen groups to interact strongly with Pb and protect PQDs from moisture/oxygen, ensuring the ambient air scalable synthesis. The 100-fold scaled-up PQDs show no significant emission shift or broadening ΔPL = 0.7 nm, ΔFWHM = 0.8 nm and remain over 80% PLQY. Also, pure-red light-emitting diode (LED) based on the scalable PQDs reserves 86.3% EQE of LEDs based on small-scale PQDs, showing the excellent batch consistency and commercial potential of PQDs.