-A A +A
Quantum dots are of growing interest as emissive materials in light-emitting devices. Here first we report the formation of highly luminescent organic capped colloidal cadmium sulfide (CdS) nanoparticles having highest photoluminescence quantum yield of69% in solutions and 34% in neat thin films in the near infrared range. Secondly, we also show efficient electroluminescence in the near infrared from solution processed hybrid light emitting diodes (LEDs) based on such colloidal CdS quantum dots embedded in an organic semiconductor matrix forming a nanocomposite active layer. We also discuss the device structure and role of the doped active layer in efficiency improvement. With optimized active layer thickness and concentration of QDs, the device exhibits an external electroluminescence quantum efficiency of 0.62% at a peak emission wavelength of 760 nm, providing a route to solution processable flexible light sources for biosensors and medicine.
American Chemical Society (ACS)
Publication date: 
1 Jan 2015

Luca Ortolani, Ashu Bansal, Lenuta Stroea, Massimiliano Lanzi, Ullrich Scherf, Emanuele Serra, Francesco Antolini, Ifor DW Samuel, Sybille Allard, Shuyu Zhang

Biblio References: 
Volume: 120 Issue: 3
J. Phys. Chem. C