by Alison Kibe
A 2013 article for Nature by Michael McGehee puts forth that perovskites (CH3NH3PbI3) – a family of semiconductor crystals – would quickly change the world of photovoltaics with their cheap and simple design. Solar cells produced for commercial use typically contain silicone semiconductors that can easily incur defects during the production process that cause efficiency losses over time and reduce the life span of a solar panel. However, they have shown the highest rates of efficiency (17 – 23%) compared to other potential semiconductor materials – until now.
As of 2013, perovskites showed great promise, with researchers producing solar cells that met a 15% efficiency benchmark. Since then, perovskite production methods have improved and perovskite based cells have only become more efficient. Less than two years later, Robert Service has written an article for Science Magazine on how researchers have discovered the power of using perovskites in conjunction with silicone semiconductors. These special types of semiconductors, termed as “tandems” for their combinatorial use of perovskites and silicone, are the latest innovation in solar voltaic cell technology. Man-Gyu Park, from Sungkynkwan University in Suwon, South Korea, was able to use them to produce cells with an efficiency rate of up to 28%.
Reaching such a high efficiency point was not easy, so tandems are not yet ready for commercial use. The most efficient tandems work by using an optical splitter to divide high and low energy light and direct each type into the perovskite cell and silicone cell respectively. But what is remarkable about this improvement and has been noted before by those involved with perovskite research, is not just greater efficiency, but the speed at which development has occurred. Even today, researchers are already aware of the next steps they can take to improve efficiency and are finding better ways to produce perovskites. With more promising electricity storage technologies like liquid batteries or the use of car batteries for storage , the use of renewable energy sources like solar may become more feasible sooner rather than later.
Service, R. Devices team up to boost solar power. Science Magazine, 347, 225 (2015).
McGehee, M. Fast-track solar cells. Nature. 501, 323-324 (2013).