Lattice-matched molecular-anchor design for high-performance perovskite quantum dot light-emitting diodes

Perovskite quantum dot light-emitting diodes have rapidly achieved high external quantum efficiencies of over 25%; however, hindered by limited operating stability originating from surface defects or ion migration in quantum dots. Here, we design a lattice-matched anchoring molecule, tris(4-methoxyphenyl)phosphine oxide (TMeOPPO-p), to anchor the multi-site defects and stabilise the lattice. The target quantum dots exhibit high exciton recombination features with near-unity photoluminescence quantum yields (97%), and the as-fabricated quantum dot light-emitting diodes present a maximum external quantum efficiency of up to 27% at 693 nm, a low efficiency roll-off (over 20% at a current density of 100 mA cm^-2 for the typical device) and an operating half-life of over 23,000 h. Besides, the air-processed devices maintain a maximum external quantum efficiency of over 26% with good storage stability. We expect this work to exert a profound influence on rational and on-demand molecule design for perovskite QDs, indicating great promise in optoelectronic applications.