Significant discovery of Demoκritοs’ Research Laboratory
Semiconductor colloidal quantum dots (CQDs) offer size- and composition-tunable luminescence of high colour purity. Importantly, their emission can be tuned deep into the second biological near-infrared (NIR-II) window (1,000–1,700 nm). However, applications are hindered by the low efficiencies achieved to date. Here, we report NIR-II CQD light-emitting diodes with an external quantum efficiency of 16.98% and a power conversion efficiency of 11.28% at wavelength 1,397 nm. This performance arises from device engineering that delivers a high photoluminescence quantum yield and charge balance close to unity. More specifically, we employed a binary emissive layer consisting of silica-encapsulated silver sulfide (Ag2S@SiO2) CQDs dispersed in a caesium-containing triple cation perovskite matrix that serves as an additional passivation medium and a carrier supplier to the emitting CQDs. The hole-injection contact also features a thin porphyrin interlayer to balance the device current and enhance carrier radiative recombination.
CONTACT INFORMATION
Dr Maria Vasilopoulou, Senior Researcher, Institute of Nanoscience and Nanotechnology, National Center for Scientific Research “Demokritos”, tel. 00 31 210 6503269, m.vasilopoulou@inn.demokritos.gr
All Highlights
NCSR "Demokritos" team among the winners of the #EUvsVirus Hackathon competition against the novel coronavirus
Award for the first Agritech Challenge Innovation Competition at Photostick Analysis
Historical Agreement for Demokritos
Startup Entrepreneurship award” for Nanometrisis P.C, a spin off company of NCSR Demokritos, during the ACCI AWARDS 2020