Controlling the shell growth mechanism and interfacial oxidation of InAs/ZnSe quantum dots for shortwave infrared emission.

Tailored shell growth and interfacial oxidation enable a highly efficient heavy-metal-free SWIR LED emitting at 1525 nm with over 55% PLQY.

• Why it matters: Efficient, scalable SWIR emitters are crucial for applications in communication, imaging, and sensing, but current devices face challenges like lattice mismatch and interfacial quenching that limit performance.
• What they did: The study employed optimized high-temperature ZnCl₂ treatment, continuous precursor injection, and controlled interfacial oxidation to improve shell nucleation, growth, and PLQY retention in InAs CQDs, along with device engineering strategies including an interlayer and doped hole-transport layer.
• The result: The resulting devices achieved a maximum external quantum efficiency of 3.5%, a record radiance of ~17 W sr−1 m−2, and a T50 lifetime of 16 hours, demonstrating a pathway to overcome current bottlenecks in colloidal SWIR emitters.