Synergistic Bulk-Surface Regulation in Perovskite Quantum Dots for Highly Efficient 1.54 μm Electroluminescence

Abstract Near-infrared (NIR) electroluminescence at 1.54 μm is vital for optical communication and bioimaging. Although CsPbCl3:Yb3+, Er3+ perovskite quantum dots (PQDs) represent a promising emitter platform, their device efficiency is hindered by intrinsically weak Er3+ emission. Here, we achieve highly efficient 1.54 μm electroluminescence via a bulk-surface dual-reconstruction strategy. Within the lattice interior, Na+ incorporation fills Pb vacancies and perturbs local crystal-field symmetry, suppressing non-radiative decay while enhancing the Er3+ and Yb3+ radiative transition rates by 7.83-fold and 3.30-fold, respectively. This boosts the Yb3+-to-Er3+ energy transfer efficiency from 15% to 56.6%. Concurrently, at the PQD surface, passivation with trifluoromethanesulfonate (OTF-) eliminates halogen vacancies via robust Lewis acid--base coordination, yielding a 45% photoluminescence quantum yield (PLQYs) at 1.54 μm. Consequently, the optimized NIR perovskite light-emitting diodes deliver a 3.27% external quantum efficiency, a 2.03 mW sr–1 cm–2 peak radiance, and an operational half-life exceeding 120 min.