Short-Wave Infrared InAs Quantum-Dot Light-Emitting Diodes with Tunable Electroluminescence beyond 1.4 μm

Near-infrared (NIR) light sources are essential across a range of fields, including biomedical imaging, night vision, therapeutics, and diagnostics. Currently, NIR light sources are mainly based on halogen lamps or costly epitaxial semiconductor devices. In addition, halogen lamps will no longer be available due to various legislative measures aimed at phasing out inefficient light sources. Emissive colloidal quantum dots (QDs) provide another alternative for creating efficient NIR light sources. However, NIR QDs mainly contain heavy metals (eg. Pb and Hg) which goes under Restriction of Hazardous Substances (ROHS) regulations. Indeed, following the entry into force of EU ROHS and the Directive ERP (CE) 244/2009 measures, interest and demand for new ROHS-compliant NIR LED-based QDs increased. In this work, we present an ROHS-compliant LED based on InAs:ZnSe core:shell QDs. The InAs cores, synthesized via a tris(dimethylamino)arsine-based continuous-injection method that enables synthesis of size-tunable large QDs, coverage SWIR spectral range. These QDs were used in four LEDs as the emissive layer, and showed Electroluminescence (EL) centered at 1007, 1275, 1300, and 1410 nm, achieving peak external quantum efficiencies of 6.2%, 3.75%, 2.04%, and 1.1%, respectively, also demonstrating EL from InAs QDs beyond 1100 nm, advancing III-V QDs for SWIR optoelectronics.