Graphene


graphene sheets, as seen on an atomic level
Graphene looks a bit like chicken wire when viewed at the atomic level. (img source)

Graphene is a form of carbon arranged in one-atom-thick sheets. On the sheet, the densely packed atoms form a sort of honeycomb pattern and this improves the material’s strength. And because graphene sheets are so thin, they’re incredibly light and flexible. A square meter sheet is just a little lighter than the average honeybee’s brain!

With solar technology, graphene is a relatively newer contender, but it’s a popular one. Graphene is much cheaper than silicon and it easily attaches to glass or plastic (common materials in solar cells).

Graphene is a carbon allotropes. Allotropes refer to the different structural forms of an element. For example, carbon can be found as diamond or as graphite. Graphene is very much like graphite: both are arranged in that honeycomb pattern, but graphite is made of many sheets of carbon, whereas graphene is made of a single sheet just one atom thick.

The name comes from Hanns-Peter Boehm, who combined the words graphite and –ene (a suffix for organic compounds in chemistry). Boehm first described the material way back in 1962. In 2010, however, Andre Geim and Konstantin Novoselov were awarded the Nobel Prize in Physics because of their experiments with two-dimensional graphene.

With solar technology, graphene is a relatively newer contender, but it’s a popular one. Graphene is much cheaper than silicon and it easily attaches to glass or plastic (common materials in solar cells).

In February 2013, Spanish researchers from Institute of Photonic Sciences published a study online in Nature Physics.

The study found that graphene is great at dislodging electrons – a key step in the photovoltaic effect – and for every photon that hit the graphene in the cells, multiple electrons were disrupted. Because of this, they predicted graphene solar cells could convert up to 60% of the sunlight absorbed into electricity.

Friendly reminder: even the best solar tech available right now can convert no more than about 40% of available sunlight.