Halide Passivation of PbS Quantum Dots in Glass for Highly Efficient NIR LEDs

Passivation of PbS quantum dots (QDs) in glasses is investigated to develop efficient near‐infrared (NIR) light sources. Passivation of QDs surface with mixed halogen is effective in enhancing the NIR photoluminescence (PL) of PbS QDs in glass over a broad NIR range (900–1800 nm). The highest internal and external quantum efficiencies recorded are 86.6 and 60.4%, respectively. Thermal and photo‐stability are markedly improved with over 65% of PL intensity retained at 373 K and threefold increased saturation excitation laser power density. These glasses are fabricated into NIR light‐emitting diodes, and their potential toward non‐destructive examination of deep biological tissues, night vision, and information encryption are successfully demonstrated.