Printable solar cells

This book provides an overall view of the new and highly promising materials and thin film deposition techniques for printable solar cell applications. The book is organized in four parts. Organic and inorganic hybrid materials and solar cell manufacturing techniques are covered in Part I. Part II is devoted to organic materials and processing technologies like spray coating. This part also demonstrates the key features of the interface engineering for the printable organic solar cells. The main focus of the Part III is the perovskite solar cells, which is a new and promising family of the photovoltaic applications. Finally, inorganic materials and solution based thin film formation methods using these materials for printable solar cell application is discussed in Part IV. © 2017 Scrivener Publishing LLC. All rights reserved

Directly Copolymerized Disulfonated Poly (arylene ether sulfone) Membranes for Vanadium Redox Flow Batteries

For the first time with this study, membranes from directly copolymerized disulfonated poly(arylene ether sulfone) (BPSH 35) were utilized to replace NafionTM in vanadium redox flow batteries (VRFB). Direct copolymerization provided exact control of the degree of disulfonation on the chemical structure. BPSH 35 showed higher proton conductivity (75 mS cm-1), lower vanadium permeability (1.6x10-13 m2 s-1) and better selectivity (4.7x1013 S m-3 s) than N212. The water uptake values for N212 and BPSH 35 membranes were 28 and 40 % by weight, respectively. Higher proton conductivity and water uptake were observed due to the higher ion exchange capacity (IEC) values of BPSH35. In spite of high water uptake of BPSH35, it showed better resistance to vanadium permeation which was most probably because of the chemically bulky nature of the membrane. Moreover, higher columbic (98.9 %) and energy efficiencies (75.6-90.3 %) at the considered current densities than N212 were achieved. Consequently, BPSH 35 membranes were successfully demonstrated as an inexpensive energy efficient candidate for VRFB

Enhanced photoelectrochemical and photocatalytic properties of 3D-hierarchical ZnO nanostructures

In the present study, highly efficient and stable photocatalysts have been developed in order to achieve both organic material degradation and sunlight-driven hydrogen generation. More specifically, we investigated the influence of the surface wettability and types of the precursor anionic species on the morphology of the three-dimensional (3D) hierarchical zinc oxide (ZnO) nanostructures. It has been observed that nitrate and acetate based anionic sources resulted with the hand fan like and nanosheet morphologies, respectively. Adhesion of the ZnO nanostructures on the FTO coated glass has been improved via potassium hydroxide treatment, which also affected the morphology of the ZnO films. Well-adhered photoelectrodes for solar water splitting on FTO coated glass substrates with high applied photon-to-current efficiency have been prepared via simple and cost effective chemical bath deposition method. Finally, ZnO nanopowders with two different morphologies have been synthesized via also chemical bath deposition. These nanopowders were used to photocatalytic degradation of methyl orange dye and very high degree of degradation (95%) was achieved using ZnO-Acetate nanopowders, which had morphology of microspheres with nanosheets. © 2017 Elsevier B.V

High performance chromium (VI) removal from water by polyacrylonitrile-co-poly (2-ethyl hexylacrylate) and polyaniline nanoporous membranes

This article reports the chromium (VI) removal from water by preparing polyacrylonitrile-co-poly (2-ethyl hexylacrylate) (PAN(92)-co-P2EHA(8)) and polyaniline (PANI) nanoporous membranes at various PANI loadings. It was observed that chromium (VI) rejections of nanoporous membranes are highly concentration and pH dependent. Almost complete chromium removal (99.9%) with higher flux values (120-177 L m-2 h-1) was observed for nanoporous membranes. Moreover, nanoporous membranes were also demonstrated as fouling resistant. Total flux loss was low and a part was attributed to reversible flux loss, which cannot cause any permanent hysteresis and easily overcome with simple washing. Scanning electron microscopy (SEM) studies were performed for identifying cross sectional morphology. It was pointed out that pore size should be small enough for filtration and optimized for higher flux but pores should be functionalized for rejection. Chemical structure, swelling ratios, sheet resistivity, and fracture morphologies of nanoporous membranes were reported. POLYM. ENG. SCI., 2012. (C) 2012 Society of Plastics Engineer

Photovoltaic performance and impedance spectroscopy analysis of CuInS2 thin film solar cells deposited on polyimide foil via spray pyrolysis

In this study, we have demonstrated that facile, cost-effective and non-vacuum spray pyrolysis technique which is available for fabricating copper indium sulfide (CuInS2) based flexible thin film solar cells for the first time in the literature. First, we have optimized the molybdenum thin films on polyimide foil to obtain proper back contacts via corona surface treatment. The sheet resistivity of the non-treated molybdenum contacts is about 3.7 ?/?. On the other hand, the sheet resistivity has decreased to 0.8 ?/? after corona treatment. The change in the electrical resistivity values of the molybdenum films on polyimide foil has become more effective after post annealing once the samples have been annealed at 300°C under atmospheric conditions. Therefore, the sheet resistivity of the films after annealing are 2.1 and 258 ?/? for corona treated and non-treated samples, respectively. After back contact optimization copper indium sulfide-indium sulfide heterojunctions has been spray pyrolyzed and a novel device structure of polyimide/Mo/CIS/Ag-In2S3/ZnO/AZO/Ag/AZO/Ni/Al has been fabricated. Impedance spectroscopy of the solar cell studies revealed that the post annealing of the absorber layer has a pronounced effect on series resistance, parallel resistance, and constant capacitance although it does not cause a significant change in the electron life time. The conversion efficiency of the 1.43% (Jsc=10.0 mA/cm2, Voc=0.52 V, FF=0.37) has been obtained in this work which proved that the facile spray pyrolysis technique is highly beneficial to fabricate flexible solar cells on polyimide substrates. Besides very low chemical precursor consumption, low equipment cost of spray technology and the device structure proposed in this work are some of the key factors while developing the large area flexible solar cells with short energy-payback time. © 2017 The Authors

Tailoring the Swelling and Glass-Transition Temperature of Acrylonitrile/Hydroxyethyl Acrylate Copolymers

Novel polyacrylonitrile (PAN)-co-poly(hydroxyethyl acrylate) (PHEA) copolymers at three different compositions (8,12, and 16 mol % PHEA) and their homopolymers were synthesized systematically by emulsion polymerization. Their chemical structures and compositions were elucidated by Fourier transform infrared, H-1-NMR, and C-13-NMR spectroscopy. Intrinsic viscosity measurements revealed that the molecular weights of the copolymers were quite enough to form ductile films. The influence of the molar fraction of hydroxyethl acrylate on the glass-transition temperature (T-g) and mechanical properties was demonstrated by differential scanning calorimetry and tensile test results, respectively. Additionally, thermogravimetric analysis of copolymers was performed to investigate the degradation mechanism. The swelling behaviors and densities of the free-standing copolymer films were also evaluated. This study showed that one can tailor the hydrogel properties, mechanical properties, and T-g's of copolymers by changing the monomer feed ratios. On the basis of our findings, PAN-co-PHEA copolymer films could be useful for various biomaterial applications requiring good mechanical properties, such as ophthalmic and tissue engineering and also drug and hormone delivery. (C) 2009 Wiley Periodicals, Inc. J AppI Polyrn Sci 116: 628-635, 201

Synthesis and Characterization of 2-Hydroxyethyl Methacrylate (HEMA) and Methyl Methacrylate (MMA) Copolymer Used as Biomaterial

A series of poly(methyl methacrylate-co-hydroxyethyl methacrylate) (PMMA-co-PHEMA), copolymers were synthesized by an emulsion polymerization technique. Copolymer compositions were determined by FT-IR and 1H-NMR spectroscopy. It was found that comonomer ratios used in the recipes were comparable within the actual copolymers. Glass transition temperatures (Tg) of PMMA-co-PHEMA copolymers were varied from 119 degrees C to 100 degrees C by increasing HEMA content. Thermogravimetric analysis showed that the copolymers were stable up to 330 degrees C. High intrinsic viscosity values of copolymer resulted in ductile solution-cast films. The hydrophilicity of the films was analyzed by water uptake measurements