Metal nanoparticles are demonstrated to boost the internal quantum effi ciency (IQE) of organic solar cells (OSCs), even without a notable plasmonic optical gain. A hybrid layer platform in combination with silver nanoparticles (AgNPs) and a polyethylenimine-ethoxylated (PEIE) layer maximize the IQE of the OSCs to nearly 100%, yielding a power conversion effi ciency (PCE) of 10.1% in the OSCs. 2D surface characterization confi rmed that the AgNPs provide a short path and funneled charge carriers to the cathode, thus effectively increasing the carrier mobility. Moreover, the hybrid layer doubles the device's half-effi ciency lifetime due to the longer retention of the improved mobility.

Efficient infrared (IR) optoelectronic devices, crucial for emerging sensing applications and also for solar energy harvesting, demand high-conductivity IR-transparent electrodes. Here we present a new strategy, one based on oxide/metal/oxide multilayers, that enables highly transparent IR electrodes. Symmetry breaking in the oxide stack leads to broad and high transmittance from visible to IR wavelengths, while a low refractive index doped oxide as a front layer boosts IR transmittance. The combination of doped oxide and ultrathin metal film allows for low sheet resistance while maintaining IR transparency. We engineer the IR microcavity effect using the asymmetric multilayer approach to tailor the distribution of incident radiation to maximize IR absorption in the colloidal quantum dot (CQD) layer. As a result, the absorption-enhanced IR CQD solar cells exhibit a photoelectric conversion efficiency of 70% at a wavelength of 1.25 μm, i.e., well within the spectral range in which silicon is blind.

In this report, we describe the fabrication of periodic Ag nanogrid electrodes by capillary assembly of silver nanoparticles (AgNPs) along patterned nanogrid templates. By assembling the AgNPs into these high-aspect-ratio nanogrid patterns, we can obtain high-aspect-ratio nanogratings, which can overcome the inherent trade-off between the optical transmittance and the sheet resistance of transparent electrodes. The junction resistance between the AgNPs is effectively reduced by photochemical welding and post-annealing. The fabricated high-aspect-ratio nanogrid structure with a line width of 150 nm and a height of 450 nm has a sheet resistance of 15.2 Ω sq(-1) and an optical transmittance of 85.4%.

Here, we demonstrate that chemical reduction of oxide layers on metal nanostructures fuses junctions at nanoscale to improve the opto-electrical performance, and to ensure environmental stability of the interconnected nanonetwork. In addition, the reducing reaction lowers the adhesion force between metal nanostructures and substrates, facilitating the detachment of them from substrates. Detached metal nanonetworks can be easily floated on water and transferred onto various substrates including hydrophobic, floppy, and curved surfaces. Utilizing the detached metal nanostructures, semitransparent organic photovoltaics is fabricated, presenting the applicability of proposed reduction treatment in the device applications.

Herein, a new methodology for solution-processed ZnO fabrication on Ag nanowire network electrode via combustion reaction is reported, where the amount of heat emitted during combustion was minimized by controlling the reaction temperature to avoid damaging the underlying Ag nanowires. The degree of participation of acetylacetones, which are volatile fuels in the combustion reaction, was found to vary with the reaction temperature, as revealed by thermogravimetric and compositional analyses. An optimized processing temperature of 180 °C was chosen to successfully fabricate a combustion-reacted ZnO and Ag nanowire hybrid electrode with a sheet resistance of 30 Ω/sq and transmittance of 87%. A combustion-reacted ZnO on Ag nanowire hybrid structure was demonstrated as an efficient transparent electrode and electron transport layer for the PTB7-Th-based polymer solar cells. The superior electrical conductivity of combustion-reacted ZnO, compared to that of conventional sol-gel ZnO, increased the external quantum efficiency over the entire absorption range, whereas a unique light scattering effect due to the presence of nanopores in the combustion-derived ZnO further enhanced the external quantum efficiency in the 450-550 nm wavelength range. A power conversion efficiency of 8.48% was demonstrated for the PTB7-Th-based polymer solar cell with the use of a combustion-reacted ZnO/Ag NW hybrid transparent electrode.