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.

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.

On-going development of carbon dots (CDs) for different applications calls for search of novel methods for their synthesis and surface functionalization. For fabrication of light-emitting devices (LEDs), CDs should be soluble in non-polar solvents that are used for ink-printing of their functional layers, apart from the obvious requirement of bright luminescence. Herein, we introduce amphiphilic CDs synthesized from a mixture of benzoic acid and ethylenediamine in acetylacetone, which satisfy both above mentioned requirements. These CDs are quasi-spherical nanoparticles 20-50 nm in size, holding aliphatic, carbonyl, amide, imine, and carbamate groups at the surface which renders them amphiphilic and soluble in a variety of substances with relative polarity ranging from 0.002 to 1, such as toluene, chloroform, alcohols, and water. By variation of the molar ratio of benzoic acid and ethylenediamine, an optimal value for photoluminescence quantum yield of 36 % in non-polar solvents is achieved. Importantly, these CDs are easily mixable with a charge transport polymer – polyvinylcarbazole, a common component of organic LEDs. As a demonstration of use of developed amphiphilic CDs in LEDs, green emitting charge-injection devices are fabricated with a broad emission band centered at 515 nm, maximal luminance of 1716 cd/m2, and ССT of 5627 K.