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

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.