Solar power generation has only a couple of detractors, cost and efficiency. Research companies have been working hard on increasing efficiency while reducing costs, and it hasn’t been an easy accomplishment. Scientists at Stanford University have produced a prototype that could address the cost problem that silicon-based solar cells experience.
Unlike the rigid glass and silicon solar panels that are currently in widespread use, Stanford’s thin-film prototype could be used to convert a surface into a photovoltaic surface, much like thin-film solar cells already in development. Additionally, unlike current thin-film technology, it is entirely made of carbon, which is far less expensive in both materials and manufacturing.
“Carbon has the potential to deliver high performance at a low cost,” said study senior author Zhenan Bao, a professor of chemical engineering at Stanford. “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.”
Typical solar cells make use of rare elements, such as silicon, or in the case of thin-film technology, indium. These materials are becoming more scarce and expensive as the demand for solar, electronics, and touch-screen devices increases.
The solar cell electrode layers, typically indium tin oxide and silver, were replaced with graphene and carbon nanotubes, while the active layer was replaced with carbon nanotubes and buckyballs. Carbon nanotubes have excellent light-absorption and electrical conductivity.
While carbon is one of the most abundant elements on earth, there is one drawback to the new solar cell prototype, its efficiency. Currently, the device only reacts to near-infrared light, giving it less than 1% electrical efficiency. Bao’s team is looking into better assembly processing, as well as developing carbon nanomaterials that react to different wavelengths of light.