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An international team of researchers has fabricated a near-2D perovskite solar cell with a special type of phenethylammonium iodide (PEAI) salt to improve hole extraction. The result is a device with an efficiency of 23.08% that, in addition, is capable of maintaining 95% of its initial efficiency after 900 hours.
An international research team has created a 3D/2D perovskite solar cell using a triple cation perovskite absorber treated with phenethylammonium iodide (PEAI), a modulator that alters the surface energy of the perovskite film and forms a quasi-structure. 2D without the need for subsequent annealing.
“We are currently planning to set up an experimental production line in Turkey,” researcher Gorkem Gunbas told pv magazine . "It could be operational in 2025."
Perovskite cells built with 2D hybrid materials are known for their stability and exhibit high exciton binding energy compared to conventional 3D devices. Different organic ammonium salts have been tested to develop 3D/2D solar cells, with halogenated analogues of PEAI salts being the preferred choice due to their potential to improve void extraction.
For their 3D/2D solar cell, the team used three organic ammonium salts: 2-methoxy-PEAI (o-OMe-PEAI), 3-methoxy-PEAI (m-OMe-PEAI), and 4-methoxy-PEAI (p -OME-PEAI). They built the device with a fluorine-doped tin oxide (FTO) substrate, a commercially pure titanium oxide (cp-TiO2) electron transport layer, a mesoporous titanium dioxide (mp-TiO2) layer, a tin(IV) oxide (SnO2) buffer, the perovskite layer, the OMe-PEAI layer, a spiro-OMeTAD hole transport layer and a gold (Au) metal contact.
“A solution of methoxy-substituted salts in isopropanol (IPA) was coated onto it by spin coating to form the 3D/2D perovskite structure,” they explained. “Perovskite films treated with methoxy-substituted salts have fewer shiny grains on the surface, indicating that the OMe-PEAI salts react with excess lead(II) iodide (PbI2) on the 3D perovskite surface” .
The resulting solar cell achieved a power conversion efficiency of 23.08%, an open circuit voltage of 1.120 V, a short circuit current of 25.55 mA/cm2, and a fill factor of 80.6%. A reference cell without PEAI treatment achieved an efficiency of 20.86%, an open circuit voltage of 1.091 V, a short circuit current of 24.55 mA/cm2, and a fill factor of 78.0%.
“All 3D/2D PSCs treated with methoxy-substituted salts showed lower hysteresis than the reference solar cell, indicating suppression of ion migration and accumulation by passivation of perovskite surface defects. the researchers stated, noting that the champion device retained 95% of its initial efficiency after 900 hours, while the reference cell only maintained 49%.
“The unique orientation of o-OMe-PEAI on the three-dimensional surface of the perovskite revealed a higher hydrophobicity compared to other salts, which in turn reflected the higher stability of the resulting devices,” they added.
The team presented the cell technology in the paper “ Drastic influence of substituent position on orientation of 2D layers enables efficient and stable 3D/2D perovskite solar cells ”. efficient and stable 3D/2D perovskite solar cells), recently published in Cell Reports Physical Science .
The team is made up of scientists from the Federal Polytechnic School of Lausanne (EPFL) (Switzerland), the Middle East Technical University (METU) (Turkey), Lomonosov Moscow State University (Russia) and the University of Tokyo (Japan). . |
