Integration of Inkjet Printed Graphene as a Hole Transport Layer in Organic Solar Cells.

This work demonstrates the green production of a graphene ink for inkjet printing and its use as a hole transport layer (HTL) in an organic solar cell. Graphene as an HTL improves the selective hole extraction at the anode and prevents charge recombination at the electronic interface and metal diffusion into the photoactive layer. Graphite was exfoliated in water, concentrated by iterative centrifugation, and characterized by Raman.

Grinding of nano-graphite inkjet inks for application in organic solar cells.

The production of printable graphene flakes is not easy to scale up when produced by ultrasonication and purified by centrifugation. In this work, natural graphite flakes were exfoliated by wet ball milling in water supported by the addition of sodium deoxycholate as a surfactant and the dispersion was formulated for inkjet printing. By subsequent dilution and filtration of the milling paste, more than 45 l of a stable dispersion of nano-graphite particles in one batch process was obtained.

Bio-Electrocatalytic Application of Microorganisms for Carbon Dioxide Reduction to Methane.

We present a study on a microbial electrolysis cell with methanogenic microorganisms adapted to reduce CO to CH with the direct injection of electrons and without the artificial addition of H or an additional carbon source except gaseous CO . This is a new approach in comparison to previous work in which both bicarbonate and gaseous CO served as the carbon source. The methanogens used are known to perform well in anaerobic reactors and metabolize H and CO to CH and water.

Electrochemical Reduction of Carbon Dioxide to Methanol by Direct Injection of Electrons into Immobilized Enzymes on a Modified Electrode.

We present results for direct bio-electrocatalytic reduction of CO2 to C1 products using electrodes with immobilized enzymes. Enzymatic reduction reactions are well known from biological systems where CO2 is selectively reduced to formate, formaldehyde, or methanol at room temperature and ambient pressure. In the past, the use of such enzymatic reductions for CO2 was limited due to the necessity of a sacrificial co-enzyme, such as nicotinamide adenine dinucleotide (NADH), to supply electrons and the hydrogen equivalent.

Self-assembly of thiophene- and furan-appended methanofullerenes with poly(3-hexylthiophene) in organic solar cells.

Novel fullerene derivatives bearing thiophene and furan residues were synthesized and studied as electron acceptor materials in bulk heterojunction organic solar cells, together with poly(3-hexylthiophene) (P3HT) as the donor polymer. Some compounds showed large nanomorphological inhomogenities in blends with P3HT; in particular, clusters with dimensions in the range of 100-1000 nm were formed. However, some blends that showed such large clusters yielded at the same time high power conversion efficiencies in photovoltaic devices, approaching 3.