Efficient colloidal quantum dot light-emitting diodes operating in the second near-infrared biological window

Autor: Anderson Emanuel Ximim Gavim, Abd. Rashid bin Mohd Yusoff, Fabio Kurt Schneider, Maria Vasilopoulou, Andreia G. Macedo, Byung Soon Kim, Athanassios G. Coutsolelos, Wilson Jose da Silva, Michael Papadakis, Hyeong Pil Kim, Mohd Asri Mat Teridi
Rok vydání: 2019
Předmět:
Zdroj: Nature Photonics. 14:50-56
ISSN: 1749-4893
1749-4885
Popis: 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. Semiconductor nanocrystals with efficient tunable emission in the 1,000–1,700 nm window could prove useful for applications in deep biological imaging and sensing.
Databáze: OpenAIRE
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