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Single material organic solar cells become an interesting area of research to overcome the challenges with efficient charge separation efficiencies in conventional organic solar cells. In this article, we have synthesized nonmetallated and metallated porphyrin-fullerene dyad materials (H2P-C60 and ZnP-C60, respectively) with simple structure, comprehensively studied their charge transfer mechanism, and established a proof of concept that nonmetallated porphyrin-fullerene dyads are better candidates to be used in organic solar cells compared with metallated dyads. Absorption and electrochemical analysis revealed the ground state electronic interactions between donor-acceptor moieties in both types of dyads. Driving force (−ΔGoET) for intramolecular electron transfer process was calculated by first oxidation and reduction potentials of dyads. The excited state electronic interactions were characterized by time-resolved fluorescence and pump-probe transient absorption experiments. Strong fluorescence quenching of porphyrin along with reduced lifetimes in dyads due to deactivation of singlet excited states by photoinduced charge transfer process between porphyrin/Zn-porphyrin core and fullerene in different polarity solvents was observed. Transient absorption spectroscopy was also applied to identify the transient spectral features, ie, cationic (H2P+/ZnP+) and anionic (C60−) radicals formed because of the charge separation in both types of dyads. Finally, organic solar cell device was also fabricated using the dyads. We obtained higher Voc, Jsc, and fill factor in single material organic solar cell using H2P-C60 compared to previous reports. [ABSTRACT FROM AUTHOR]

Organic solar cell research has attracted scientific and commercial interest in the last decade due to a rapid increase in power conversion efficiencies (PCEs). Today, PCEs in the range of 8 - 1 0% have been obtained using conjugated polymers as electron-donor materials in combination with fullerene/other acceptors. However, to enable commercial applications, the efficiencies and lifetimes of organic solar cells still need to be improved significantly. In recent years, due to the potential advantages of Se-containing conjugated materials, namely, lower band gaps, rigidity, and strong Se-Se integration, have attracted surprising attention for use in organic solar cells. In this review, we focus on the synthesis and applications of Se-containing conjugated polymers for organic solar cells and throughout compare them with S- and O-containing analogues where applicable. The relationships between the chemical structures and properties, such as absorptions, energy levels, mobilities, and photovoltaic behavior, are also discussed. [ABSTRACT FROM AUTHOR]

Organic solar cell research has attracted scientific and commercial interest in the last decade due to a rapid increase in power conversion efficiencies (PCEs). Today, PCEs in the range of 8-10?% have been obtained using conjugated polymers as electron-donor materials in combination with fullerene/other acceptors. However, to enable commercial applications, the efficiencies and lifetimes of organic solar cells still need to be improved significantly. In recent years, due to the potential advantages of Se-containing conjugated materials, namely, lower band gaps, rigidity, and strong Se···Se integration, have attracted surprising attention for use in organic solar cells. In this review, we focus on the synthesis and applications of Se-containing conjugated polymers for organic solar cells and throughout compare them with S- and O-containing analogues where applicable. The relationships between the chemical structures and properties, such as absorptions, energy levels, mobilities, and photovoltaic behavior, are also discussed. [ABSTRACT FROM AUTHOR]

The use of oppositely charged colloidal nanoparticles to build multilayered structures is an approach in thin film science. In this work, uniform spherical nano-dispersions of gold (ca. 20 nm) and silica (ca. 30 nm) were synthesised with specific volume concentration to achieve colloidal stability. Exploiting the use of self-assembly, multilayers of these oppositely charged nanoparticles were built using alternate coating with chitosan. Gold nanoparticles have strong optical absorption in visible region of electromagnetic spectrum resulting from its surface plasmon resonance. Silica nanoparticles have low refractive index and absorb light mostly in the ultraviolet (UV) region. The optical absorption band of the fabricated thin films extends from UV to visible region of the electromagnetic spectrum. The spectral characteristics of these thin-film assemblies are a combination of thickness and the order of the layers in a stack. These films have potential applications as optical elements and in optoelectronics. © 2011 Canadian Society for Chemical Engineering [ABSTRACT FROM AUTHOR]

Significance: A transformative platform is reported to derive ultra‐thin carbon molecular sieve (CMS) hollow fiber membranes from dual‐layer precursor hollow fibers with independently tuned skin layer and substrate properties. These ultra‐thin CMS hollow fiber membranes show attractive CO2/CH4 separation factors and excellent CO2 permeances up to ~1,400% higher than state‐of‐the‐art asymmetric CMS hollow fiber membranes. They provide a unique combination of permeance and selectivity competitive with zeolite membranes, but with much higher membrane packing density and potentially much lower costs. [ABSTRACT FROM AUTHOR]

Review: [synthesis and applications of Se-containing conjugated polymers for organic solar cells; 95 refs. [ABSTRACT FROM AUTHOR]