Silicon is the most abundant chemical element on Earth after oxygen. It is also the main element for the manufacture of the photovoltaic solar panel. As a semiconductor, it is of crucial importance, but nevertheless has its limits. Today, the industry is getting closer to it and the efficiency of the products is reaching its climax. Within the Helmholtz Association, Germany’s largest research group, the testing of a new principle gives reason for optimism.
A solution exists and improves the capacities of the solar panels so that they reach 32.5%. This is the result obtained by the tests carried out by the scientific team in Berlin, where a new technology of solar cells is imagined to reinvent solar panels. The idea is not to completely review the format of the cells, but to boost them with the help of a mineral called Perovskite and composed of titanium and calcium. Its structure quickly gained interest in global solar energy research. In addition to being lighter, thinner and easier to produce, it would also be better able to capture certain wavelengths from the sun than silicon.
To capture the entire solar spectrum, the pair perovskite and silicon would therefore be particularly interesting. Blue light for perovskite, red and infrared for silicon. From this observation, the Helmholtz Zentrum in Berlin imagined a cell stacking on top of each other layers of both perovskite and silicon. The diagram is very easy to understand (see below). In the end, at 32.5% capacity, the technology of the German research laboratory does better than the previous record which reached 31.25% in 2021 (and another 30% a year earlier). In barely two years, the solar panel has drawn a bright future, forgive me the pun.
© Helmholtz Zentrum Berlin
Cooperation rather than rivalry
It is interesting to understand how two elements with identical principles do not end up in a rivalry, but in a tandem. Perhaps one day, the elements between the active area and the cell electrodes will be totally different, but so far the perovskite/silicon duo seems to be the most effective and economical solution. With the advent of decentralized electricity from virtual power plants, the market is leaping.
In four years, the engineers and scientists of the Helmholtz Zentrum have become leaders in this research and we owe them all of the recent records in terms of cell efficiency. A quick look in the rearview mirror is enough to make us realize how technology has advanced at breakneck speed. In 2015, the efficiency record for a photovoltaic cell was only 13.7%. And we were already talking, at the time, of tandem cells… In 2018, the record reached 25.2%. The measurements were all recorded by an independent firm, and listed by the National Renewable Energy Lab (NREL), which has been monitoring the evolution of solar cells since 1976.
