Smooth composite transparent electrodes are fabricated via lamination of silver nanowires into the polymer poly‐(4,3‐ethylene dioxythiophene):poly(styrene‐sulfonate) (PEDOT:PSS). The surface roughness is dramatically reduced compared to bare nanowires. High‐efficiency P3HT:PCBM organic photovoltaic cells can be fabricated using these composites, reproducing the performance of cells on indium tin oxide (ITO) on glass and improving the performance of cells on ITO on plastic.

We demonstrate organic photovoltaic cells in which every layer is deposited by solution processing on opaque metal substrates, with efficiencies similar to those obtained in conventional device structures on transparent substrates. The device architecture is enabled by solution-processed, laminated silver nanowire films serving as the top transparent anode. The cells are based on the regioregular poly(3-hexylthiophene) and C(61) butyric acid methyl ester bulk heterojunction and reach an efficiency of 2.5% under 100 mW/cm(2) of AM 1.5G illumination. The metal substrates are adequate barriers to moisture and oxygen, in contrast to transparent plastics that have previously been used, giving rise to the possibility of roll-to-roll solution-processed solar cells that are packaged by lamination to glass substrates, combining the cost advantage of roll-to-roll processing with the barrier properties of glass and metal foil.

High-efficiency white OLEDs fabricated on silver nanowire-based composite transparent electrodes show almost perfectly Lambertian emission and superior angular color stability, imparted by electrode light scattering. The OLED efficiencies are comparable to those fabricated using indium tin oxide. The transparent electrodes are fully solution-processable, thin-film compatible, and have a figure of merit suitable for large-area devices.

We demonstrate the time- and concentration-dependent dissolution (etching) of polyelectrolyte multilayer (PEM) films comprised of poly(allylamine hydrochloride) (PAH) and poly(acrylic acid) (PAA) immersed in NaCl solutions. PEM thickness decreases to a reproducible unchanging value that depends upon the initial film thickness and the concentration of NaCl. As opposed to a “top-down” removal of PEM chains from the film, the dissolution mechanism involves the diffusion and association of chains throughout the PEM that leave the film in the form of polyelectrolyte complexes (PECs). The PEC phase diagram is invoked to explain the observations presented in this paper and work by previous researchers. We demonstrate the straightforward application of PEM salt etching to pattern films where the spatial position and amount of dissolved material are controlled, resulting in a multicolor reflector and a gradient-thickness film. In addition to providing a more comprehensive picture of PEM stability, these results may help to advance the technological impact of PEMs in biology and other fields where the ability to create gradients in film thickness could be advantageous.

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