Near Infrared Light‐Emitting Diodes Based on Colloidal InAs/ZnSe Core/Thick‐Shell Quantum Dots

• Published in: Advanced science Vol. 11; no. 23; pp. e2400734 - n/a
• Main Authors: Roshan, Hossein, Zhu, Dongxu, Piccinotti, Davide, Dai, Jinfei, De Franco, Manuela, Barelli, Matteo, Prato, Mirko, De Trizio, Luca, Manna, Liberato, Di Stasio, Francesco
• Format: Journal Article
• Language: English
• Published: Germany John Wiley and Sons Inc 01.06.2024; Wiley
• Subjects: Core/shell; InAs; Light‐emitting diodes; Near‐infrared; Quantum Dots; Restriction of hazardous substances (RoHS) compliant; Restriction of hazardous substances (RoHS) compliant; Core/shell; Near‐infrared; Quantum Dots; InAs; Light‐emitting diodes
• ISSN: 2198-3844; 2198-3844
• DOI: 10.1002/advs.202400734

Heavy‐metal‐free III–V colloidal quantum dots (QDs) exhibit promising attributes for application in optoelectronics. Among them, InAs QDs are demonstrating excellent optical performance with respect to absorption and emission in the near‐infrared spectral domain. Recently, InAs QDs attained a substantial improvement in photoluminescence quantum yield, achieving 70% at a wavelength of 900 nm through the strategic overgrowth of a thick ZnSe shell atop the InAs core. In the present study, light‐emitting diodes (LEDs) based on this type of InAs/ZnSe QDs are fabricated, reaching an external quantum efficiency (EQE) of 13.3%, a turn‐on voltage of 1.5V, and a maximum radiance of 12 Wsr−1m−2. Importantly, the LEDs exhibit an extensive emission dynamic range, characterized by a nearly linear correlation between emission intensity and current density, which can be attributed to the efficient passivation provided by the thick ZnSe shell. The obtained results are comparable to state‐of‐the‐art PbS QD LEDs. Furthermore, it should be stressed not only that the fabricated LEDs are fully RoHS‐compliant but also that the emitting InAs QDs are prepared via a synthetic route based on a non‐pyrophoric, cheap, and commercially available as precursor, namely tris(dimethylamino)‐arsine. Core/shell InAs/ZnSe Quantum Dots (QDs) synthesized via tris(dimethylamino)‐arsine route demonstrate remarkable emission properties. Light‐emitting diodes (LEDs) based on such QDs show emission at 896 nm with an external quantum efficiency of 13.3%, and maximum radiance of 12 Wsr−1m−2. Notably, the fabricated LEDs are compliant with the European directive on “Restrictions of Hazardous Substances in Electrical and Electronic Equipment” (RoHS).