Solution-Processed OLED Based on a Mixed-Ligand Europium Complex

An approach to increase the efficiency of europium-based OLEDs was proposed through the formation of a mixed-ligand complex. The design of a series of europium complexes, together with an optimization of the solution deposition, including the host selection, as well as the variation of the solvent and deposition parameters, resulted in a noticeable increase in OLED luminance. As a result, the maximum luminance of the Eu-based OLED reached up to 700 cd/m², which is one of the highest values for an Eu-based solution-processed OLED. Finally, its stability was investigated.

Organic Solar Cells Improved by Optically Resonant Silicon Nanoparticles

Silicon nanophotonics has become a versatile platform for optics and optoelectronics. For example, strong light localization at the nanoscale and lack of parasitic losses in infrared and visible spectral ranges make resonant silicon nanoparticles a prospect for improvement in such rapidly developing fields as photovoltaics. Here, we employed optically resonant silicon nanoparticles produced by laser ablation for boosting the power conversion efficiency of organic solar cells. Namely, we created colloidal solutions of spherical nanoparticles with a range of diameters (80-240 nm) in different solvents. We tested how the nanoparticles' position in the device, their concentration, silicon doping, and method of deposition affected the final device efficiency. The best conditions optimization resulted in an efficiency improvement from 6% up to 7.5%, which correlated with numerical simulations of nanoparticles' optical properties. The developed low-cost approach paves the way toward highly efficient and stable solution-processable solar cells.