Improved Sheet Resistance of Nanofiber-Based Transparent Conducting Electrodes Using Silver Nanowires

There is an increased need for research on flexible transparent electrodes (FTEs) because they are critical to next-generation electronic devices, such as wearable computers. In this study, highly conductive transparent conducting electrodes, based on polyvinylidene fluoride (PVDF) nanofiber webs treated with poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) and silver nanowires (AgNWs), were successfully fabricated. Transparent conducting electrodes (TCEs) were obtained by a brush-painting process using different weight ratios of a AgNWs to PEDOT:PSS solution, and the surface, electrical, optical, and chemical properties, as well as the tensile strength of the samples, were determined. It was found that the electrical conductivity of the samples improved as the AgNW content increased, but the light transmittance decreased. In this work, there was a slight decrease in the optical properties and a considerable increase in the electrical properties due to the hybridization of AgNWs and PEDOT:PSS, compared to using only PEDOT:PSS. When considering both transparency and electrical conductivity, which are essential parameters of TCEs, sample PA2, which was treated by mixing AgNWs and PEDOT:PSS/dimethyl sulfoxide (DMSO) in a ratio of 1:5 (16.67 wt% of AgNWs), was found to be the best sample, with a sheet resistance of 905 Ω/cm2 and light transmittance of 79%.

Fabrication of junction-free Cu nanowire networks via Ru-catalyzed electroless deposition and their application to transparent conducting electrodes

Over the past few years, metal nanowire networks have attracted attention as an alternative to transparent conducting oxide materials such as indium tin oxide for transparent conducting electrode applications. Recently, electrodeposition of metal on nanoscale template is widely used for formation of metal network. In the present work, junctionless Cu nanowire networks were simply fabricated on a substrate by forming a nanostructured Ru with 80nm-width as a seed layer, followed by direct electroless deposition of Cu. By controlling the density of Ru nanowires or the electroless deposition time, we readily achieve desired transmittance and sheet resistance values ranging from ~1 kΩ/sq at 99% to 9 Ω/sq at 89%. After being transferred to flexible substrates, the nanowire networks exhibited no obvious increase in resistance during 8000 cycles of a bending test to a radius of 2.5 mm. The durability was verified by evaluation of its heating performance. The maximum temperature was greater than 180°C at 3 V and remained constant after three repeated cycles and for 10 min. Transmission electron microscopy and X-ray diffraction studies revealed that the adhesion between the electrolessly deposited Cu and the seed Ru nanowires strongly influenced the durability of the core-shell structured nanowire-based heaters.

Transparent Conducting Electrodes for Optoelectronic Devices: State-of-the-art and Perspectives

This chapter brings a concise review of the transparent conducting materials, films and electrodes (TCM, TCF and TCE, respectively), its state-of-the-art and outlooks ahead. Initial part of the chapter gives a general introduction of the topic, followed by a feasible road map as proposed and collated by the authors based on several other reviews. Fundamental physics behind the transparent conductors is discussed in the latter part. Established and potential oxide based TCMs, namely the transparent conducting oxides (TCOs) are reviewed which are being used commercially and will see application in the near future. Non-conventional TCMs, which are mostly non-TCOs, such as graphene, carbon nanotubes (CNT), metallic nanowires (MNWs) and their hybrids are described in brief. Scalability and large area fabrication which are most important concerns for commercialization of TCMs are discussed. The general prospects are given at the end.