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This paper aims to describe two manufacturing techniques for selective patterning of Poly‐3‐4‐ethyleneoxythiophene/poly‐4‐sytrensulfonate (PEDOT/PSS) for flexible electronic applications. The paper also includes methods to tailor the electrical conductivity of the patterned polymeric films.

Line patterning and inkjet printing methods were used to pattern PEDOT/PSS onto mechanically flexible substrates including polyethylene terephthalate, polyimide and paper.

PEDOT/PSS thin films with controlled spatial resolution and strong adhesion passing a laboratory Scotch‐tape test were patterned onto flexible substrates using both line patterning and inkjet printing techniques. After annealing, the sheet resistivities of patterned PEDOT/PSS lines increased slightly. Treating the electrodes with ethylene glycol dramatically increased the electrical conductivity.

There has been extensive work on selective deposition of solution processable active materials onto mechanically flexible substrates. Many techniques including line patterning and inkjet printing are currently being used to fabricate devices for flexible electronic applications. However, there is a need for tailoring the electrical conductivity of the patterned polymeric active materials.

In this study, two very cost effective methods for the selective deposition of the water soluble PEDOT/PSS onto flexible substrates with controlled spatial resolution and electrical conductivity are reported.

Purpose This study aims to apply the impedance spectroscopy (IS) for analyzing the electrical behavior and extracting the equivalent circuit of single-layer flexible organic light-emitting diodes (OLEDs) with poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) anode.

The preliminary ultraviolet (UV) treatment of the flexible substrate of polyethylene terephthalate (PET) influenced the conductivity of PEDOT:PSS anodes.

The IS showed that the OLED with UV-treated PET/PEDOT:PSS anodes had lower values of the contact resistance and higher value of the interface capacitance.

The obtained data were used for modeling of flexible OLEDs with polymeric anodes and calculation of important display parameters such as pixel refresh ratio, signal delays and energy losses due to contact resistances. These parameters were compared for PEDOT:PSS anodes deposited on PET treated and non-treated by UV.

The purpose of this study is use to density functional theory (DFT) to investigate the molecular adsorption by PEDOT:PSS for different doping levels. DFT calculations are performed using the SIESTA code. In addition, the non-equilibrium Green’s function method is used within the TranSIESTA code to determine the quantum transport properties of molecular nanodevices.

Density functional theory (DFT) is used to investigate the molecular adsorption by PEDOT:PSS for different doping levels. DFT calculations are performed using the SIESTA code. In addition, the non-equilibrium Green’s function method is used within the TranSIESTA code to determine the quantum transport properties of molecular nanodevices.

Simulation results show very good sensitivity of Pd-doped PEDOT:PSS to ammonia, carbon dioxide and methane, so this structure cannot be used for simultaneous exposure to these gases. Silver-doped PEDOT:PSS structure provides a favorable sensitivity to ammonia in addition to exhibiting a better selectivity. If the experiment is repeated, the sensitivity is increased for a larger concentration of the applied gas. However, the sensitivity will decrease at a higher ratio than smaller concentrations of gas.

The advantages of the proposed sensor are its low-cost implementation and simple fabrication process compared to other sensors. Moreover, the proposed sensor exhibits appropriate sensitivity and repeatability at room temperature.

Design, fabricate and evaluate all-solid-state wearable sensor systems that can monitor ion concentrations in human sweat to provide real time health analysis and disease diagnosis capabilities.

A human health monitoring system includes disposable customized flexible electrode array and a compact signal transmission-processing electronic unit.

Patterned rGO (reduced-graphene oxide) layers can replace traditional metal electrodes for the fabrication of free-standing all solid film sensors to provide improved flexibility, sensitivity, selectivity, and stability in ion concentration monitoring. Electrochemical measurements show the open circuit potential of current selective electrodes exhibit near Nernst responses versus Na+ and K+ ion concentration in sweat. These signals show great stability during a typical measurement period of 3 weeks. Sensor performances evaluated through real time measurements on human subjects show strong correlations between subject activity and sweating levels, confirming high degree of robustness, sensitivity, reliability and practicality of current sensor systems.

In improving flexibility, stability and interfacial coherency of chemical sensor arrays, rGO films have been the developed as a high-performance alternative to conventional electrode with significant cost and processing complexity reduction. rGO supported solid state electrode arrays have been found to have linear potential response versus ion concentration, suitable for electrochemical sensing applications. Current sweat sensor system has a high degree of integration, including electrode arrays, signal processing circuits, and data visualization interfaces.

The purpose of this paper is to develop a capacitor fully integrated into a wearable textile fabric for the application on smart clothing.

A small capacitor with stainless steel yarns as the electrodes and poly-(3,4–ethylenedioxythiophene): polystryrene sulphonate (PEDOT:PSS) as the dielectric material has been made, integrated into a textile fabric. The electric performance of the capacitor was analyzed and compared with other kinds of electric capacitors.

The fabricated small, PEDOT:PSS capacitor could finally power a calculator for 37 s with the energy stored in it.

This finding is of an important significance for a further development on the capacitor with a better performance.

The purpose of this paper is to demonstrate the influence of annealing treatment on the photovoltaic properties of the solar cell based on ITO/PEDOT:PSS/ZnO:P3HT/Ag.

The influence of the annealing temperature and time on the P3HT/ZnO interface morphology and the ITO/PEDOT:PSS/ZnO:P3HT/Ag solar cell performance was discussed. The morphology and the current‐voltage (J‐V) characteristics were investigated by atomic force morphology (AFM) and solar simulator with an AM 1.5 G filter under an irradiation intensity of 100 mW cm⁻². The light intensity was calibrated using a standard silicon photovoltaic solar cell.

The photovoltaic performances were found to have been greatly enhanced by an annealing treatment at 145°C for 30 min.

The paper demonstrates that the annealing treatments play a crucial role in improving the morphology and J‐V performance of the ITO/PEDOT:PSS/ZnO:P3HT/Ag solar cell.

There is a developing interest in flexible sensors, especially in the new and intelligent generation of textiles. The purpose of this paper is to fabricate a flexible capacitive sensor on a PET fabric and to investigate some affecting factor on its performance.

PET fabric, coated with graphite or with graphite/PEDOT:PSS, was applied as electrodes. Two types of electrospun nanoweb layers from polyamide and polyvinyl alcohol polymers were used as dielectrics. Some factors including electrode area, fabric conductivity, fabric roughness, dielectric thickness, dielectric insulation type and vertical pressure were considered as independent variables. The capacity of the sensor and its detection threshold considered as the outcome (response) variables. Control samples were fabricated by using aluminum plates and cellulosic layer as electrodes and dielectric, respectively.

Results showed that post-coating with PEDOT:PSS would improve the conductivity of electrodes up to 300 Ω in comparison with just graphite-coated samples. It was also found that either by improving the conductivity or increasing the area of electrode plates the sensitivity of sample would be increased in pressure stimulating tests.

The fabric sensor showed remarkable response toward pressure with a lower detection threshold of 30mN/cm² (obtained capacity ~ 4×104 pF) in comparison with aluminum electrode sensors.

The study aims to carry out the production of a bulk heterojunction organic solar cell in a laboratory scale using a blend of poly (3-hexylthiopene) (P3HT) and [6, 6]-phenyl (C61) butyric acid methyl ether (PCBM).

Four inverted geometry organic solar cells were prepared based on 1:1 ratio of P3HT to PCBM and subjected to post annealing at different temperatures of 32, 120, 130 and 140°C. Solar cells were fabricated with structure glass/ITO/P3HT:PCBM/PEDOT:PSS/Au and characterized using Keithley 2400 series sourcemeter and a multimeter interfaced to a computer system with a LabVIEW software, which showed both dark and illumination current–voltage characteristic curves. Four reference cells were also fabricated with structure soda lime glass/P3HT:PCBM and annealed at different temperatures of 32, 120, 130 and 140°C.

The third organic solar cell prepared, Sample CITO, had the best performance with power conversion efficiency (PCE) of 2.0281 per cent, fill factor (FF) of 0.392, short circuit current of −0.0133 A and open circuit voltage of 0.389 V. Annealing of active layer was found to improve cell morphology, FF and PCE. Annealing of the active layer at 140°C resulted in a decrease of the PCE to 2.01 per cent.

These findings are in good agreement with previous investigation in literature which reported that best annealing temperature for a 1:1 ratio blend of active material is 130°C. Ultraviolet–visible spectra on reference cells showed that sample CITO had wider absorption spectra with peak absorbance at a wavelength of 508 nm.

This research is purely original.

The purpose of this paper is to study the optical and electrical characteristics of a single-junction solar cell based on a green-colour dye vanadyl 2,9,16, 23-tetraphenoxy-29H, 31H-phthalocyanine (VOPcPhO). The use of soluble vanadyl phthalocyanine derivative makes it very attractive for photovoltaic applications due to its tunable properties and high solubility.

A photoactive layer of VOPcPhO has been sandwiched between indium tin oxide (ITO) and aluminium (Al) electrodes to produce a ITO/PEDOT:PSS/VOPcPhO/Al photovoltaic device. The VOPcPhO thin film is deposited by a simple spin coating technique. To obtain the optimal thickness for the solar cell device, different thicknesses of the photoactive layer, achieved by manipulating the spin rate, have been investigated.

The device exhibited photovoltaic effect with the values of Jsc, Voc and FF equal to 5.26 × 10-6 A/cm2, 0.621 V and 0.33, respectively. The electronic parameters of the cell have been obtained from the analysis of current-voltage characteristics measured in dark. The values of ideality factor and barrier height were found to be 2.69 and 0.416 eV, respectively. The optical examination showed that the material is sensitive to light in the UV region between 270 nm and 410 nm, as well as in the visible spectrum within the range of 630 nm and 750 nm.

The solar cell based on a single layer of vanadyl phthalocyanine derivative results in low efficiency, which can be enhanced by introducing a variety of donor materials to form bulk heterojunction solar cells.

The spin coating technique provides a simple, less expensive and effective approach for preparing thin films.

A novel thin-film, single-junction organic solar cell, fabricated by using VOPcPhO, has been investigated for the first time ever. The vanadyl phthalocyanine derivative together with a donor material will have potential application for improved efficiency of the solar cells.

The purpose of this paper is to fabricate an ethanol sensor which has bio-friendly and eco-friendly properties compared to the commercially available ethanol sensors.

This paper describes the construction of a highly sensitive ethanol sensor with low ppm level detection at room temperature by integrating three techniques. The first deals with the formation of organic/inorganic p-n heterojunction. Second, tuning of structural parameters such as length, diameter and density of Zinc Oxide (ZnO) nanostructure was achieved through introduction of the Fe dopant into a pure ZnO seed layer. Furthermore, ultra-violet (UV) light photoactivation approach was used for enhancing the sensing performance of the fabricated sensors. Four different sensors were fabricated by combing the above approaches. The structural, morphological, optical and material compositions were characterized using different characterization techniques. Sensing behavior of the fabricated sensors toward ethanol was experimented at room temperature with and without UV illumination combined with stability studies. It was observed that all the fabricated sensors showed enhanced sensing performance for 10 ppm of ethanol. In specific, FNZ (Fe-doped ZnO seeded Ni-doped Zn nanorods) sensor exhibited a higher response at 2.2 and 13.5 s for 5 ppm and 100 ppm of ethanol with UV light illumination at room temperature, respectively. The photoactivated FNZ sensor showed quick response and speedy recovery at 18 and 30 s, respectively, for 100 ppm ethanol.

In this study, the authors have experimentally analyzed the effect of Fe (in ZnO seed layer and ZnO NRs) and Ni (in ZnO NRs) dopants in the room temperature sensing performance (with and without UV light) of the fabricated ethanol sensors. Important sensing parameters like sensitivity, recovery and response time of all the fabricated sensors are reported.

The Fe doped ZnO seeded Ni doped Zn nanorods (FNZ sample) showed a higher response at 2.2 s and 13.5 s for very low 5 ppm and 10 ppm of ethanol at room temperature under UV light illumination when compared to the other fabricated sensors in this paper. Similarly, this sensor also had quick response (18 s) and speedy recovery (30 s) for 100 ppm ethanol.