Chinese researchers have built a large-area perovskite solar panel that is said to retain more than 90% of its original efficiency after more than 850 hours. They used a hydrophobic, all-organic salt to modify the top surface of large-area gap-covered methylammonium-free halide perovskite layers.
“A large area perovskite solar modules have problems with their stability internal point defects and a number of surface imperfections during the manufacturing process,” researcher Prem Jyoti Singh Rana said pv magazine.
Researchers used a hydrophobic, all-organic salt known as fluorinated anilinium benzylphosphonate (FABP) modify the surface of methylammonium (MA)-free halide covered with gaps perovskite layers. The salt acts as a molecular lock capable of binding to both anion and cation vacancies, which significantly increases the inherent stability of the materials.
“It not only reduces entry of external species such as oxygen and moisture, but also prevents their exit volatile Organic components during the heat stability testing,” the researchers said, noting that the absence of MA is a crucial factor because it tends to undergo chemistry that leads to volatile and electrochemically reactive products.
The research group built two different modules an active within the precincts of / 58.5 cm2 and 64 cm2, respectively. The first achieved a power conversion efficiency of 19.28% and the second 17.62%.
“Unencapsulated FABP-based devices show excellent heat resistance, retaining 80% and 70% of their original power conversion efficiency after 2700 hours and 1700 hours at 65 C and 85 C, the researchers explained. “Unencapsulated FABP-based mini-modules show approximately 80% efficiency retention after 7500 hours (313 days) at less than 30% relative humidity (RH). They also retain significantly more than 90% of original efficiency for over 850 hours continuously measuring below light lighting.”
The scientists presented the module in the paper “Molecular Locking with All-Organic Surface Modifiers Enables Stable and Efficient Slot Die-Coated Methylammonium-Free Perovskite Solar Modules,” published recently Advanced materials.
“FABP-treated PSMs retained an impressive over 90% Initial efficiency after more than 850 hours of exposure in continuous 1 sunlightwhich proves the effectiveness of this new generation non-halide-based passivator in increasing the stability of perovskites through strong binding and secondary interaction between both organic molecules and perovskite surfaces,” they concluded.