Organic photovoltaics (OPVs) die due to their interactions with environmental gases, i.e., moisture and oxygen, the latter being the most dangerous, especially under illumination, due to the fact that most of the active layers used in OPVs are extremely sensitive to oxygen. In this work we demonstrate solution-based effective barrier coatings based on composite of poly(vinyl butyral) (PVB) and mica flakes for the protection of poly (3-hexylthiophene) (P3HT)-based organic solar cells (OSCs) against photobleaching under illumination conditions. In the first step we developed a protective layer with cost effective and environmentally friendly methods and optimized its properties in terms of transparency, barrier improvement factor, and bendability. The developed protective layer maintained a high transparency in the visible region and improved oxygen and moisture barrier quality by the factor of ~7. The resultant protective layers showed ultra-flexibility, as no significant degradation in protective characteristics were observed after 10 K bending cycles. In the second step, a PVB/mica composite layer was applied on top of the P3HT film and subjected to photo-degradation. The P3HT films coated with PVB/mica composite showed improved stability under constant light irradiation and exhibited a loss of <20% of the initial optical density over the period of 150 h. Finally, optimized barrier layers were used as encapsulation for organic solar cell (OSC) devices. The lifetime results confirmed that the stability of the OSCs was extended from few hours to over 240 h in a sun test (65 °C, ambient RH%) which corresponds to an enhanced lifetime by a factor of 9 compared to devices encapsulated with pristine PVB.

A number of different research methodologies have been developed to increase the conductivity and mechanical properties of stretchable or flexible conductors. One of the promising techniques recommended for applying metallic nanoparticles (NPs) to PDMS (polydimethylsiloxane) substrate is to develop a thin-film that gives possible conductivity and good mechanical strain. This article discusses the preparation of silver nanoparticles using the chemical reduction method with silver nitrate as the precursor, and uses glucose as a reducing agent. In addition, polyvinyl pyrrolidone (PVP) is used to prevent the nanoparticles’ oxidation and agglomeration once they have been synthesized successfully. Moreover, we utilize the power of diethylamine to accelerate the evolution of nanoparticles, and deionized water is used to prevent any possible contamination. The prepared Ag-NPs are then deposited on the solidified PDMS substrate through sintering. A multimeter is used to measure the electrical resistance. Ag-NPs are confirmed by UV-Vis at a 400-nm peak. Furthermore, we discuss the surface morphologies, particle sizes and thicknesses of the film and substrate when studied using different microscopy techniques. The prepared stretchable conductor is found to be suitable to use in biosensing and electronic devices.

In this study, zirconium was incorporated into βNiAl bulk alloys via electric arc melting process. The study aims to understand the functioning of Zr-doped bulk metallic alloys in terms of microstructural evolution, hardness, corrosion and oxidation resistance. Bulk alloys were selected since there are no interdiffusion phenomena as in the case of actual superalloys. XRD analysis was carried out to confirm the formation of metallic β-NiAl alloys where various concentration of Zr affects the crystal lattice structure. Results show successful preparation of βNiAl bulk alloys; however, a non-uniform distribution was noticed in the microstructures of the alloys oxidized at higher temperatures i.e., 10500C and 11500C and also the increasing trend of hardness was observed by the addition of zirconium content. In addition, significant oxide growth and severe spallation was observed in the samples having no or very high zirconium content. Even comparably the sample that contained no zirconium showed better oxidation resistance than that of their higher zirconium counterparts except appropriately doped sample i.e., 0.1 wt. % Zr. One of the other features observed was very brittle behavior for the samples of higher zirconium content. The extensive discussion is presented in the light of findings that were noted in this study.