It is known that ultrathin ͑Ͻ10 nm͒ metal films ͑UTMFs͒ can achieve high level of optical transparency at the expense of the electrical sheet resistance. In this letter, we propose a design, the incorporation of an ad hoc conductive grid, which can significantly reduce the sheet resistance of UTMF based transparent electrodes, leaving practically unchanged their transparency. The calculated highest figure-of-merit corresponds to a filling factor and a grid spacing-to-linewidth ratio of 0.025 and 39, respectively. To demonstrate the capability of the proposed method the sheet resistance of a continuous 2 nm Ni film ͑Ͼ950 ⍀ / ᮀ͒ is reduced to ϳ6.5 ⍀ / ᮀ when a 100 nm thick Cu grid is deposited on it. The transparency is instead maintained at values exceeding 75%. These results, which can be further improved by making thicker grids, already demonstrate the potential in applications, such as photovoltaic cells, optical detectors and displays.

Transparent conductors are essential in many optoelectronic devices, such as displays, smart windows, light-emitting diodes and solar cells. Here we demonstrate a transparent conductor with optical loss of ∼1.6%, that is, even lower than that of single-layer graphene (2.3%), and transmission higher than 98% over the visible wavelength range. This was possible by an optimized antireflection design consisting in applying Al-doped ZnO and TiO2 layers with precise thicknesses to a highly conductive Ag ultrathin film. The proposed multilayer structure also possesses a low electrical resistance (5.75 Ω sq−1), a figure of merit four times larger than that of indium tin oxide, the most widely used transparent conductor today, and, contrary to it, is mechanically flexible and room temperature deposited. To assess the application potentials, transparent shielding of radiofrequency and microwave interference signals with ∼30 dB attenuation up to 18 GHz was achieved.

An effective method to deposit atomically smooth ultrathin silver (Ag) films by employing a 1 nm copper (Cu) seed layer is reported. The inclusion of the Cu seed layer leads to the deposition of films with extremely low surface roughness (<0.5 nm), while it also reduces the minimum thickness required to obtain a continuous Ag film (percolation thickness) to 3 nm compared to 6 nm without the seed layer. Moreover, the Cu seed layer alters the growth mechanism of the Ag film by providing energetically favorable nucleation sites for the incoming Ag atoms leading to an improved surface morphology and concomitant lower electrical sheet resistance. Optical measurements together with X-ray diffraction and electrical resistivity measurements confirmed that the Ag film undergoes a layer-by-layer growth mode resulting in a smaller grain size. The Cu seeded Ag growth method provides a feasible way to deposit ultrathin Ag films for nanoscale electronic, plasmonic and photonic applications. In addition, as a result of the improved uniformity, the oxidation of the Ag layer is strongly reduced to negligible values.

Polycrystalline graphene and metallic nanowires (NWs) have been proposed to replace indium tin oxide (ITO), the most widely used transparent electrode (TE) film on the market. However, the trade-off between optical transparency (Topt) and electrical sheet resistance (Rs) of these materials taken alone makes them difficult to compete with ITO. In this paper, we show that, by hot-press transfer of graphene monolayer on Ag NWs, the resulting combined structure benefits from the synergy of the two materials, giving a Topt-Rs trade-off better than that expected by simply adding the single material contributions Ag NWs bridge any interruption in transferred graphene, while graphene lowers the contact resistance among neighboring NWs and provides local conductivity in the uncovered regions in-between NWs. The hot-pressing not only allows graphene transfer but also compacts the NWs joints, thus reducing contact resistance. The dependence on the initial NW concentration of the effects produced by the hot press process on its own and the graphene transfer using hot press was investigated and indicates that a low concentration is more suitable for the proposed geometry. A TE film with Topt of 90% and Rs of 14 Ω/sq is demonstrated, also on a flexible glass substrate about 140 μm thick, a very attractive platform for efficient flexible electronic and photonic devices.

Transparent electrodes (TEs) having electrooptical trade‐offs better than state‐of‐the‐art indium tin oxide (ITO) are continuously sought as they are essential to enable flexible electronic and optoelectronic devices. In this work, a TiO2‐Ag‐ITO (TAI)‐based TE is introduced and its use is demonstrated in an inverted polymer solar cell (I‐PSCs). Thanks to the favorable nucleation and wetting conditions provided by the TiO2, the ultrathin silver film percolates and becomes continuous with high smoothness at very low thicknesses (3–4 nm), much lower than those required when it is directly deposited on a plastic or glass substrate. Compared to conventional ITO‐TE, the proposed TAI‐TE exhibits exceptionally lower electrical sheet resistance (6.2 Ω sq−1), higher optical transmittance, a figure‐of‐merit two times larger, and mechanical flexibility, the latter confirmed by the fact that the resistance increases only 6.6% after 103 tensile bending cycles. The I‐PSCs incorporating the TAI‐TE show record power conversion efficiency (8.34%), maintained at 96% even after 400 bending cycles.