Researchers say graphene will outperform ITO as solar panel transparent electrode material

Researchers from Singapore's A*STAR institute discovered that graphene outperforms ITO as solar panels transparent electrodes. The researchers say that stacking four graphene sheets is the best method - as more graphene sheets decrease the resistance but blocks more light.

A single graphene sheets blocks less than 3% of light which means more light can reach the solar panel. Graphene's efficiency as a solar panel electrode depends on the type of light absorbed by the panel. For solar panels that absorb near-infrared light graphene is only slightly less effective than ITO, while graphene would be ideally suited to photovoltaic cells with a very broad absorption range, such as a recently developed organic solar cell that can harvest light from 350 to 850 nanometers.

New GNR-based magnetic field-effect transistor

Researchers from Singapore's A*STAR Institute developed a new graphene ribbons (GNRs) based magnetic field-effect transistor (it responds to changes in a magnetic field).

The basic idea is to use two armchair-edged GNRs joined end to end. One of the ribbons acts as a metallic conductor while the other one (which is wider) acts as a semiconductor. The existence of a magnetic field makes this device conductive.

Graphene may have potentially adverse environmental and health risks

Sweden's Department of Energy and Environment studied the available information on graphene, and came up with the conclusion that the new material may have potentially adverse environmental and health risks. Graphene could exert a considerable toxicity and it is also suggested that graphene is both persistent and hydrophobic (graphene is a very effective water repellent).

There are still many risk-related knowledge gaps to be filled, according to the researchers as "Considerable" emissions of graphene from electronic devices and composites are possible in the future.

Graphene with Graphone domains can be used to pack molecules

Researchers from Singapore's A*STAR institute and the US have designed a new way to pack molecule using graphene and graphone (graphene that is hydrogenated on one side) structures. The idea is to use a graphene sheet with a graphone domain that can be used to trap molecules. This is achievable because the graphone region is distorted in 3D to form a cap shape and it is stable well above room temperature.

In the research they used fullerenes as model molecules. It turns out that you can trap several molecules in the same graphone domain. This kind of structure can be useful for energy storage or biological applications.

Graphene Oxide may be toxic, kills bacteria

Some scientists are concerned that Graphene may be hazardous and toxic - for humans, animals and the natural environment. Researchers from Singapore's A*STAR have published a study on how graphite, graphite oxide, graphene oxide and reduced graphene oxide may effect bacteria (Escherichia coli in the study).

The researchers showed that the graphene-based materials kill substantially more bacteria than graphite-based materials. Graphene Oxide was the most dangerous material. The researchers say that most of the E.coli cells were individually wrapped by layers of graphene oxide. In contrast, E. coli cells were usually embedded in the larger reduced-graphene-oxide aggregates (see image above).

Versarien - Think you know graphene? Think again! Versarien - Think you know graphene? Think again!