Comment résoudre le problème de dégradation des performances des cellules solaires en pérovskite ?

Perovskite solar cells hold promise for improved photoelectric conversion efficiency, but they suffer from one of the biggest drawbacks—their performance degrades over time when exposed to sunlight. A team of scientists from the United States, China and South Korea wrote in the latest issue of "Nature" that they had performed a simple treatment on the surface of perovskite solar cells, solved the problem of degradation, and cleared the way for the application of thin-film solar cell technology. the biggest obstacle.

Perovskites are a group of materials that have the same atomic arrangement (crystal structure) as the mineral perovskite oxides. Metal halide perovskites, one of the "family members", are prepared for their great application potential in the field of high-efficiency and energy-saving thin-film solar cells. attention. Perovskite solar cells are much cheaper to manufacture than silicon-based solar cells, but they have one of the biggest drawbacks – their performance degrades when exposed to light for a long time. If this problem can be properly addressed, it will help solar technology. "Fly into the homes of ordinary people".

Yang Yang, the head of the latest research and a professor of materials science and engineering at the University of California, Los Angeles, explained that for solar cell defects, the common treatment method currently used by scientists is to deposit a layer of organic ions on the surface to make the surface negatively charged. While this treatment was designed to improve the energy-conversion efficiency of perovskite solar cells, it also allowed too many electrons to accumulate on the cell's surface. This destabilizes the orderly arrangement of atoms, making perovskite solar cells less and less efficient over time, ultimately rendering them uncommercial.

À la lumière de cette découverte, l'équipe a trouvé un moyen de remédier à la dégradation de la batterie en associant des ions chargés positivement à des ions chargés négativement à la surface, ce qui a rendu les électrons de surface plus neutres et stables.

L'équipe a testé la durabilité des cellules solaires traitées dans des conditions qui accélèrent le vieillissement des cellules et dans des conditions qui simulent la lumière du soleil par tous les temps. Les résultats ont montré que les cellules maintenaient 87 % de leur efficacité de conversion photoélectrique initiale pendant plus de 2 000 heures. En revanche, dans les mêmes conditions et pour la même durée, la performance des cellules solaires non traitées a chuté à 65 % .

"Our perovskite solar cells are among the most stable in efficiency reported to date, and our latest research lays the groundwork for the commercialization and widespread adoption of perovskite solar cell technology," said the researchers. On the basis of further developing and perfecting this technology, we can design more stable perovskite solar cells."