Abstract: Photovoltaic cells comprising an active layer comprising, as p-type material, conjugated polymers such as polythiophene and regioregular polythiophene, and as n-type material at least one fullerene derivative. The fullerene derivative can be C60, C70, or C84. The fullerene also can be functionalized with indene groups. Improved efficiency can be achieved.

Abstract: Photovoltaic cells comprising an active layer comprising, as p-type material, conjugated polymers such as polythiophene and regioregular polythiophene, and as n-type material at least one fullerene derivative. The fullerene derivative can be C60, C70, or C84. The fullerene also can be functionalized with indene groups. Improved efficiency can be achieved.

Abstract: Photovoltaic cells comprising an active layer comprising, as p-type material, conjugated polymers such as polythiophene and regioregular polythiophene, and as n-type material at least one fullerene derivative. The fullerene derivative can be C60, C70, or C84. The fullerene also can be functionalized with indene groups. Improved efficiency can be achieved.

Abstract: The present invention generally relates to nanostructure compositions, as well as methods for the controlled synthesis of nanostructures, such as carbon nanotubes. In some embodiments, methods involving iterative growth of a nanostructure template to homogeneously produce nanostructure compositions are provided. The compositions may include nanostructures having a specific length, width, diameter, ring orientation, and/or other characteristics. Using methods described herein, nanostructures (e.g., nanotubes) having uniform properties, such as electrical conductivity, may be readily produced. The ability to provide homogeneous nanostructure compositions may be advantageous in the design and fabrication of numerous materials and electronic devices.