A technique for determining the materialspecific morphology of a polymer−fullerene blend is presented. This technique is applied to solution processed bulk-heterojunction organic solar cells with different weight ratios of polymer−fullerene blend using the PTB7:PCBM material system. Optical and electrical characterizations show that the light absorption increases for larger polymer (PTB7) content, while the fill factor of the fabricated solar cells is improved for larger fullerene (PCBM) content. The materialspecific morphologies of polymer−fullerene bulk-heterojunctions are measured by employing AFM phase imaging. The measured AFM phase images reveal that fullerene material forms flake-like clusters which are embedded in the polymer network. The size of the flakes is increasing with larger content of fullerene material. By correlating the optical and electrical properties with the measured bulk-heterojunction morphologies, the relation between bulk-heterojunction structure and solar cell performances is discussed.

The strong immediate phototoxicity of acid violet reflects its clinical toxicity. Bromophenol blue might also be disadvantageous for patient outcome because of its delayed phototoxicity. The other dyes (trypan blue, brilliant blue g, and indocyanine green) were not found to be toxic neither with exposure to ambient light nor after exposure to light of intensities used in surgery.

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Optical properties of organic materials such as polymer–fullerene mixtures enable realization of semi-transparent photodetectors with superior design and features for standing wave spectrometer applications.

This work shows an analytical semiconductor diode model suitable to describe photovoltaic cells for a large variety of physical parameters, such as mobility of charge carriers and illumination intensity. The model is based on a simplified drift-diffusion calculation assuming a constant electric field and a linear increasing current inside the semiconductor layer. The model also accounts for recombination processes in the active and contact layers. Organic and inorganic solar cells can be accurately modeled, which is confirmed by comparison of experimental data and full drift-diffusion calculations with the same physical parameters. In addition, this model shows how physical properties can be directly extracted from the crossing point often found in J-V characteristics.