Ultra-thin foldable transparent electrodes composed of stacked silver nanowires embedded in polydimethylsiloxane

We have prepared an ultra-thin flexible transparent conductive electrode with high folding endurance composed of randomly arranged silver nanowires (AgNWs) embedded in polydimethylsiloxane (PDMS). A simple preparation method was performed to connect a glass substrate coated with a AgNW network and a glass substrate coated with PDMS. The glass substrate was then removed after the PDMS solidified, and the AgNW–PDMS composite film was peeled off. Moreover, the problem of the high contact resistance caused by the random arrangement of AgNWs was solved by the local joule heat generated by applying voltage to both sides of the AgNW–PDMS composite structure to weld the overlapping AgNWs. The sheet resistance (Rs ) of AgNW–PDMS composite films with different AgNW deposition concentrations decreased by 46.4%–75.8% through this electro-sintering treatment. The embedded structure of the AgNW–PDMS composite ensures better voltage resistance and environmental stability under high temperature and humidity conditions compared with a AgNW network attached to a glass substrate. Additionally, the substrate-free, excellent elasticity and high resilience characteristics resulted in the Rs value of the same composite electrode only increasing by 2.9 ohm/sq after folding four times. The advantage of the metal thermal conductivity makes the joule heat generated by electric injection rapidly diffuse and dissipate in the AgNW-based transparent heater with faster response time and smaller voltage drive than indium tin oxide.

Improving the bending resistance of double-layer printed flexible OLEDs with PEDOT: PSS-PEO composite HIL films

Flexible organic light-emitting diodes (OLEDs) are expected to have excellent device performance and mechanical robustness in many areas, such as wearable electronics and display devices. For the traditional materials of OLED anode, ITO is undoubtedly the most mature transparent conductive electrode available. However, the brittle and rigid nature of ITO severely limit the development of flexible OLED. In this work, a solution blending film consisting of poly (3,4 ethylenedioxythiophene): poly (styrene sulfonate) (PEDOT: PSS) and poly (ethylene oxide) (PEO) was used as a hybrid hole injection layer, where PEO polymer in the composite films can greatly improve the bending resistance of device. The printed flexible OLEDs doped with PEO exhibit impressive mechanical durability, maintaining 80.4% of its maximum external quantum efficiency after 1000 bends at a radius of curvature of 10 mm, compared to 46.3% for the counterpart without PEO doping.

Fabrication and Investigating the Electrical and Optical Properties of Silver Nanowire/Indium Tin Oxide Transparent Conductive Electrodes

In this study, we analyze the optical and electrical properties of silver nanowires/indium tin oxide transparent conductive electrode (TCE). Silver nanowire was synthesized by polyol method. ITO was deposited by direct-current sputtering. The diameter and length of the synthesized silver nanowire are in the range of 40-70 nm and 5-30 μm, respectively. The silver nanowire TCEs have a rather high resistance (~ 210 Ω /). After a layer of indium tin oxide sputtered on silver nanowire TCE, the resistance dropped sharply (~ 30.1 Ω/◻) corresponding to 84.1% transmittance at 550 nm. The figure of merit of this TCE is 68.3. This result shows that the fabricated silver naowire/indium tin oxide TCEs have great potential in application as window electrodes for solar cells and LED devices.

Influence of Ag interlayer Thickness on the Optical, Electrical and Mechanical Properties of Ti-doped In2O3/Ag/Ti-doped In2O3 Multilayer Flexible Transparent Conductive Electrode

Transparent and conductive Ti-doped In2O3 (TIO)/Ag/Ti-doped In2O3 (TAT) multilayer films were deposited on colorless poly imide (CPI) substrates by direct current (DC) and radio frequency (RF) magnetron sputtering at room temperature. During deposition the thickness of both the top and bottom TIO layer was fixed at 30 nm, while the thickness of the Ag interlayer was varied, to 5, 10, and 15 nm, to enhance the optical, electrical and mechanical properties of the films. In the XRD analysis the TIO films did not show any characteristic peaks in the diffraction pattern. The 10 nm thick Ag inter layer showed some characteristic peaks of Ag (111), (200), (220) and (311), respectively, and the grain size of the Ag interlayer enlarged as Ag thickness increased. To investigate the most efficient Ag interlayer thickness, a figure of merit (FOM) based on the opto-electrical performance of the transparent conducting films was compared. The films with a 10 nm thick Ag interlayer exhibited a higher FOM of 1.71 × 10-2 Ω-1 than the other films. When the radius of the film's curvature was reduced to 1.7 mm, the TIO single layer films showed a 13 times increase in sheet resistance, while the TAT (30/10/30 nm) films showed an insignificant change in sheet resistance. From the observed results, it was concluded that the Ag interlayer in the TAT multilayer films enhanced the opto-electrical performance of the films and also acted as a potent bridge which assured the high flexibility endurance of the films.

Nucleobases thin films deposited on nanostructured transparent conductive electrodes for optoelectronic applications

Environmentally-friendly bio-organic materials have become the centre of recent developments in organic electronics, while a suitable interfacial modification is a prerequisite for future applications. In the context of researches on low cost and biodegradable resource for optoelectronics applications, the influence of a 2D nanostructured transparent conductive electrode on the morphological, structural, optical and electrical properties of nucleobases (adenine, guanine, cytosine, thymine and uracil) thin films obtained by thermal evaporation was analysed. The 2D array of nanostructures has been developed in a polymeric layer on glass substrate using a high throughput and low cost technique, UV-Nanoimprint Lithography. The indium tin oxide electrode was grown on both nanostructured and flat substrate and the properties of the heterostructures built on these two types of electrodes were analysed by comparison. We report that the organic-electrode interface modification by nano-patterning affects both the optical (transmission and emission) properties by multiple reflections on the walls of nanostructures and the electrical properties by the effect on the organic/electrode contact area and charge carrier pathway through electrodes. These results encourage the potential application of the nucleobases thin films deposited on nanostructured conductive electrode in green optoelectronic devices.