Scientists at Stanford University have built the world's first all-carbon solar cell. Because carbon offers a combination of low cost and high performance, it is a viable alternative to current photovoltaic materials, which are expensive. This new solar cell is made from materials such as carbon nanotubes and "buckyballs".
Said Zhenan Bao, the study's senior author, "Carbon has the potential to deliver high performance at a low cost. To the best of our knowledge, this is the first demonstration of a working solar cell that has all of the components made of carbon. This study builds on previous work done in our lab." Silicon solar panels are rigid, while the newly-built solar cell is a thin film that "can be coated from solution."
According to Bao, in the future we could see these new flexible carbon solar cells coated on various surfaces, such as windows, rather than the rigid silicon panels often seen on roofs. The solar cell itself uses graphene and carbon nanotubes rather than indium tin oxide electrodes, a material that is becoming more expensive and scarce as demand grows. The active layer is also composed of carbon nanotubes, as well as carbon molecules called buckyballs.
The study's co-author Michael Vosgueritchian said, "Every component in our solar cell, from top to bottom, is made of carbon materials. Other groups have reported making all-carbon solar cells, but they were referring to just the active layer in the middle, not the electrodes." So what's the downside? For now at least, the all-carbon cell is inefficient, mostly absorbing almost infrared wavelengths and offering a lab efficiency under 1-percent. According to Bao, the researchers have a long way to go in terms of efficiency, which they expect to increase by utilizing better processing techniques and materials.