Can anything be a solar panel?
“The short answer is, it can be,” says Ahmad. “Practically any surface can be covered with semiconductors and used to harvest light. From newspaper, textiles, to the building wall and car roof.” You need two things to make a solar panel: a conducting surface, and light harvesting materials. Most photovoltaic (PV) technology is based on silicone. This technology has been in development since the 1950s, and silicone cells have since increased dramatically in efficiency, and lowered in cost. Yet silicon solar panels are inflexible, and demand high-purity silicon and high-temperature processing, making it difficult to cover many objects in them. The next generation of PV cells are expected to be based on a family of crystals known as perovskites. These tiny crystals can be put into flexible material so that – in theory – anything could become a solar panel. There are already two or three companies printing perovskites with inkjet printing, says Ahmad. Perovskite-based solar cells can work with artificial light, albeit not as effectively, and absorb light across a wide range of the spectrum. The hope is that as the efficiency of these cells increases to that of silicon technology, solar energy harvesting will become even more common, and not be restricted to large panels. While silicon-based PV cells have a thickness of 200-300 micrometres, perovskite cells only need to be half a micrometre thick to achieve a similar performance. In the EU-funded SMILIES project, funded by the Marie Skłodowska-Curie Actions programme, Ahmad and his colleagues improved the performance of perovskite solar cells using graphene-like backing material. In his European Research Council-funded MOLEMAT project, Ahmad and his team are working on a full value chain of perovskites from materials to devices. Perovskite cells are sorely needed: to meet our future energy demands, the world needs 1 000 times more PV energy than silicon-based panels are providing today, Ahmad says. If and when these handy, flexible solar harvesters arrive, you can expect solar energy to be gathered all around you – perhaps even from the newspaper you are reading, or the clothes you wear. Click here to find out more about Shahzada Ahmad’s research: Bringing perovskite solar cells closer to commercialisation.
Keywords
SMILIES, solar, silicon, perovskites, PV, panels, absorb, light, harvest