by Dylan Goodman
Recent research from Stanford University has produced a promising new outlook on Solar Panel efficiency. Perovskite, a mineral composed of calcium titanate, has been found to increase the efficiency of conventional solar cells. Functionally, solar cells work by converting light energy, in the form of photons, into electrical energy. With the future of energy uncertain, this extremely unique process allows humans to harness energy from the sun, a non-diminishing resource. If the technology to exist to harness the suns energy with perfect efficiency, we could easily power the entire planet.
Conventional solar cells, constructed mostly of silicon materials, absorb and convert both the visible spectrum as well as infrared light. However, this process is not always extremely efficient. While the non-visible light spectrum does contain energy, it is relatively low compared to the energy of visible light. Researchers hope to use perovskite to increase the overall efficiency of conventional solar cell technology. According to research by Stanford University scientists, by laying perovskites on top of existing silicon solar cells, they’ve been able to increase the efficiency of energy conversion by up to 50%. The process works by layering multiple solar cells on top of each other. While the bottom of such panels will consist of conventional silicon solar cells, the upper layer will be made of perovskites. Light passes through each level of the multilayer cells, and the silicone and perovskite are able to absorb different parts of the spectrum with increased efficiency. In doing so, the use of multiple materials allows for layered cells to convert substantially more light into energy. With the proper combination, efficiency can be improved by up to 50%.
Unfortunately, the long term stability of perovskites is largely unknown. While silicone is a rock and can be heated to high temperatures with no risk, perovskite will degrade if exposed to light or water. While the technology is not ready to produce perovskite cells designed to last the 25 years of a conventional panel, research looks promising in developing a more durable cell in the next 5-10 years.
Bailie, Colin D. et al. ‘Semi-Transparent Perovskite Solar Cells For Tandems With Silicon And CIGS’. Energy Environ. Sci. 8.3 (2015): 956-963. Web. 24 Mar. 2015.