Ag-nanowire films coated with ZnO nanoparticles as a transparent electrode for solar cells

Abstract

We demonstrate that solution-processible silver-nanowire films coated with zinc-oxide-nanoparticles (ZnO-NPs) can be used as transparent electrodes in organic photovoltaic devices. The ZnO-NP coating acts as electron extraction layer and as encapsulating agent, protecting the wires from oxidation and improving their mechanical stability. Scanning photocurrent microscopy showed photocurrent generation to be more efficient at the active material surrounding the wires. Ultra-violet illumination as present in the solar spectrum was found to enhance photocurrent by improving the ZnO in-layer conductivity through the photoconductive effect. Inverted polythiophene:fullerene devices using ZnO-NP coated silver-nanowires or indium-tin-oxide as transparent electrode reached power conversion efficiencies of 2.4%.

Metallic nanowire networks: effects of thermal annealing on electrical resistance

“…This idea has already been considered with thin transparent oxide films (ZnO or TiO 2 ) for which slightly higher thermal stability was achieved. 25 Finally the quantitative estimation of the different kinetics involved for each physical mechanism would enable better separation of their relative influences and would help calculating their importance during thermal annealing. This could yield an efficient way to foresee the evolution of the morphological and electrical properties of metallic NW networks as induced by thermal annealing and allow further optimization of the physical properties of metallic NW networks.…”

Controlling the Electronic Interface Properties in Polymer–Fullerene Bulk Heterojunction Solar Cells

“…N-type metal oxides like (doped) ZnO and TiO X are a suitable and stable material group that can fulfill these requirements. The application of TiO X and intrinsic ZnO as buffer layers for AgNWs are already reported [114,118]. Leem et al successfully applied TiO X as buffer layer for an electrode using NWs from Cambrios Technologies Corporation with comparable properties to those NWs used in this study [118].…”

“…AgNWs [114]. Because of the high roughness of this electrode, a very thick active layer (400 nm) was needed to reduce shunts.…”

“…Due to the low sheet resistance, high transmittance and solution processing, silver nanowires (AgNWs) are considered as highly promising candidates to replace brittle and expensive sputtered indium-tin-oxide (ITO) [114][115][116][117][118][119]. The AgNW percolation type electrode needs to be filled with a buffer layer to smooth out the roughness, to adjust the work function and provide charge selectivity.…”

Silver nanowire networks: Physical properties and potential integration in solar cells

“…[21][22][23][24] As mentioned, high haze factors result in light scattering into the device and increases the effective absorption cross section. The ability of AgNW networks to produce high haze networks while maintaining sufficient electro-optical properties shows the real potential to integrate them into solar cells.…”