Current solar panels are mainly made of silicon, boasting an efficiency of about 22%, which means they can convert just over a fifth of solar energy into electricity. However, silicon production is costly and energy-intensive.
A promising alternative is emerging: perovskite. This synthetic semiconductor material can convert much more solar energy than silicon and at a lower cost.
A recent article, published in the journal
Nature Energy by researchers from the University of Colorado at Boulder and their international colleagues, unveils an innovative method for manufacturing these new perovskite solar cells, marking a crucial step toward the commercialization of this technology.
One strategy to increase the efficiency of solar cells involves stacking perovskite cells on top of traditional silicon cells, creating tandem cells. This combination, absorbing different parts of the solar spectrum, could increase panels' efficiency by more than 50%.
However, a major challenge lies in the process of applying semiconductors onto glass plates, which traditionally must be done in an environment filled with non-reactive gases to prevent the perovskites from reacting with oxygen, diminishing their performance.
A recent discovery allows semiconductors to be applied outside these controlled conditions. This is possible thanks to the addition of dimethylammonium formate, or DMAFo, to the perovskite solution, preventing the materials' oxidation. This breakthrough brings perovskite cells made with DMAFo up to the level of current record-holding cells, achieving an efficiency of nearly 25%.
In terms of durability, commercial silicon panels retain at least 80% of their performance after 25 years. Perovskite cells, being more reactive, degrade more quickly in air. However, the study shows that perovskite cells treated with DMAFo retain 90% of their efficiency after being exposed to LED light simulating sunlight for 700 hours, compared to only 300 hours for those made without DMAFo. A step in the right direction, though there is still progress to be made to compete with silicon cells.
A decade of research on perovskites now allows these cells to reach an efficiency that is comparable, if not better, than that of silicon cells invented 70 years ago.