This paper compares rates of charge transport across self-assembled monolayers (SAMs) of n-alkanethiolates having odd and even numbers of carbon atoms (n odd and n even ) using junctions with the structure M TS /SAM//Ga 2 O 3 /EGaIn (M = Au or Ag). Measurements of current density, J(V), across SAMs of n-alkanethiolates on Au TS and Ag TS demonstrated a statistically significant odd−even effect on Au TS , but not on Ag TS , that could be detected using this technique. Statistical analysis showed the values of tunneling current density across SAMs of n-alkanethiolates on Au TS with n odd and n even belonging to two separate sets, and while there is a significant difference between the values of injection current density, J 0 , for these two series (log|J 0Au,even | = 4.0 ± 0.3 and log|J 0Au,odd | = 4.5 ± 0.3), the values of tunneling decay constant, β, for n odd and n even alkyl chains are indistinguishable (β Au,even = 0.73 ± 0.02 Å ). A comparison of electrical characteristics across junctions of n-alkanethiolate SAMs on gold and silver electrodes yields indistinguishable values of β and J 0 and indicates that a change that substantially alters the tilt angle of the alkyl chain (and, therefore, the thickness of the SAM) has no influence on the injection current density across SAMs of n-alkanethiolates.

Dispersing an ionic transition metal complex into an elastomeric matrix enables the fabrication of intrinsically stretchable light-emitting devices that possess large emission areas (∼175 mm(2)) and tolerate linear strains up to 27% and repetitive cycles of 15% strain. This work demonstrates the suitability of this approach to new applications in conformable lighting that require uniform, diffuse light emission over large areas.

We present new flexible, transparent, and conductive coatings composed of an annealed silver nanowire network embedded in a polyurethane optical adhesive. These coatings can be applied to rigid glass substrates as well as to flexible polyethylene terephthalate (PET) plastic and elastomeric polydimethylsiloxane (PDMS) substrates to produce highly flexible transparent conductive electrodes. The coatings are as conductive and transparent as indium tin oxide (ITO) films on glass, but they remain conductive at high bending strains and are more durable to marring and scratching than ITO. Coatings on PDMS withstand up to 76% tensile strain and 250 bending cycles of 15% strain with a negligible increase in electrical resistance. Since the silver nanowire network is embedded at the surface of the optical adhesive, these coatings also provide a smooth surface (root mean squared surface roughness<10 nm), making them suitable as transparent conducting electrodes in flexible light-emitting electrochemical cells. These devices continue to emit light even while being bent to radii as low as 1.5 mm and perform as well as unstrained devices after 20 bending cycles of 25% tensile strain.

The emergence of flexible and stretchable optoelectronics has motivated the development of new transparent conductive electrodes (TCEs) to replace conventional brittle indium tin oxide. For modern optoelectronics, these new TCEs should possess six key characteristics: low cost, solution-based processing; high transparency; high electrical conductivity; a smooth surface; mechanical flexibility or stretchability; and scalable, low-cost patterning methods. Among many materials currently being studied, silver nanowires (AgNWs) are one of the most promising, with studies demonstrating AgNW films and composites that exhibit each of the key requirements. However, AgNW-based TCEs reported to date typically fulfill two or three requirements at the same time, and rare are examples of TCEs that fulfill all six requirements simultaneously. Here, we present a straightforward method to fabricate AgNW/polymer composite films that meet all six requirements simultaneously. Our fabrication process embeds a AgNW network patterned using a solution-based wetting–dewetting protocol into a flexible or stretchable polymer, which is then adhered to an elastomeric poly­(dimethylsiloxane) substrate. The resulting patterned AgNW/polymer films exhibit ∼85% transmittance with an average sheet resistance of ∼15 Ω/sq, a smooth surface (a root-mean-square surface roughness value of ∼22 nm), and also withstand up to 71% bending strain or 70% stretching strain. We demonstrate the use of these new TCEs in flexible and stretchable alternating current electroluminescent devices that emit light to 20% bending strain and 60% stretching strain.

This roadmap includes the perspectives and visions of leading researchers in the key areas of flexible and printable electronics. The covered topics are broadly organized by the device technologies (sections 1-9), fabrication techniques (sections 10-12), and design and modeling