TOP‐Zn Steric Hindrance Effect Enables Ultra‐Uniform CsPbX 3 Quantum Dots for Wide‐Color Gamut Displays

Abstract Perovskite quantum dots (PQDs) are expected to be an ideal candidate for wide‐color gamut displays owing to their high color purity. However, their color purity is challenged by remarkable spectral broadening due to non‐uniform size distribution and crystal defects. Here, a ligand‐ion (TOP‐Zn) complex‐modulating nucleation strategy is proposed to depress spectral broadening. This is achieved by enhancing the steric hindrance effect during lead‐halogen octahedral assembly and reducing the reaction activity/sites of the system. This strategy is universal and has been confirmed to be effective for blue, green, and red PQDs, achieving narrowed spectral full‐width‐at‐half‐maximum (FWHM) of 15, 17, and 25 nm, respectively. These FWHMs are record‐breaking and contribute to a wide color gamut coverage of ≈130% National Television Standards Committee and ≈100% Rec. 2020 standard. Meanwhile, these PQD‐based light‐emitting diodes (PeLEDs) exhibit a high external quantum efficiency (EQE) of exceeding 20% at their pure color range. These results provide a feasible path to achieve ultra‐uniform and pure‐color luminescent PQDs for wide‐color gamut displays.