Perovskite and Perovskite solar cells
Peroovskite is described by Wikipedia as follows: “Perovskite (pronunciation: /pəˈrɒvskaɪt/) is a calcium titanium oxide mineral composed of calcium titanate (Ca Ti O3). It lends its name to the class of compounds which have the same type of crystal structure as CaTiO3 (XIIA2+VIB4+X2−3), known as the perovskite structure.[5] Many different cations can be embedded in this structure, allowing the development of diverse engineered materials.[6]”
Wikipedia’s entry on the related solar cells is in part as follows: “A perovskite solar cell is a type of solar cell which includes a perovskite structured compound, most commonly a hybrid organic-inorganic lead or tin halide-based material, as the light-harvesting active layer.[1][2] Perovskite materials such as methylammonium lead halides and all-inorganic cesium lead halide, are cheap to produce and simple to manufacture.”
The efficiency of devices that use these materials has risen from just 3.8 percent in 2009 to 23.3 percent in late 2018. In silicon-based tandem cells the efficiency has reached 27.3 percent. These Perovskite solar cells are the fastest advancing solar energy technology today. They have the potential of even better efficiencies with very low production costs.
Oxford PV and Swift Solar
Oxford PV is a startup working with Oxford University. It received $3 million from the UK government to develop the new technology. Just two days ago another company in the US, Swift Solar, raised $7 million to help bring the technology to the commercial market as shown in a Securities and Exchange Commission filing.
The new Perovskite solar cells contain the first new technology to come along for years that can offer better efficiency in converting light to electric power at a much lower cost than existing technologies.
Sam Stranks, the lead scientific adviser and a co-founder of Swift Solar said: “Perovskite has let us truly rethink what we can do with the silicon-based solar panels we see on roofs today. Another aspect that really excites me: how cheaply these can be made. These thin crystalline films are made by mixing two inexpensive readily abundant salts to make an ink that can be deposited in many different ways… This means that perovskite solar panels could cost less than half of their silicon counterparts.”
The Perovskite material was first incorporated in solar cells by Japanese researchers in 2009 but they had low efficiencies and lacked stability rendering them of no use to industry. However, in the last nine years this has all changed as the stability of compounds has been vastly improved and efficiency has grown dramatically.
Improvements in efficiency and lower costs make commercial use viable
Oxford PV is working to develop Perovskite solar cells that would achieve conversion efficiency of 37 percent. This is much better efficiency than existing polycrystalline photovoltaic or thin-film voltaic cells. Up until now the new technology has been too costly to compete with the mass production in China pushed by the Chinese government. However, the reductions in costs and improved efficiency of the new technology will now begin to lure investors who can see it as a viable commercial alternative to the existing cells.
Oxford PV’s Chris Case said in a statement: “Today, commercial-sized perovskite-on-silicon tandem solar cells are in production at our pilot line and we are optimizing equipment and processes in preparation for commercial deployment.”
