Scientists establish 3D/2D perovskite solar cell with 23.08% efficiency thanks to PEAI salt

• A worldwide research group that includes scientists from EPFL in Switzerland, Middle East Technical University (METU) in Turkey, Lomonosov Moscow State University in Russia as well as The University of Tokyo has actually produced a quasi-2D perovskite solar cell with a unique type of salt to enhance hole extraction.

The triple-cation perovskite absorber was treated with phenethylammonium iodide (PEAI), a modulator that alters the perovskite film's surface power and also develops a quasi-2D framework without additional annealing. The result is a 23.08%-efficient device that is likewise able to maintain 95% of its first effectiveness after 900 hours.

The scientists specified that they are currently planning to set up a speculative assembly line in Turkey, that could be operational as quickly as 2025.

For their 3D/2D solar cell, the group made use of 3 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 layer, the perovskite layer, the OMe-PEAI layer, a spiro-OMeTAD hole transport layer, as well as a gold (Au) metal contact.

The team defined the process, stating that a remedy of methoxy-substituted salts in isopropanol (IPA) was coated on it by spin coating to form the 3D/2D perovskite structure. Perovskite films treated with methoxy-substituent salts have a tendency to have fewer brilliant grains on the surface, suggesting that OMe-PEAI salts respond with excess lead(II) iodide (PbI2) on the 3D perovskite surface.

The resulting solar cell attained a power conversion effectiveness of 23.08%, an open-circuit voltage of 1.120 V, a short-circuit current of 25.55 mA/cm2, and a fill element of 80.6%. A reference cell without the PEAI treatment got to a performance of 20.86%, an open-circuit voltage of 1.091 V, a short-circuit current of 24.55 mA/cm2, and also a fill element of 78.0%.

According to the team, all 3D/2D PSCs treated with methoxy-substituted salts revealed lower hysteresis than the reference solar cell, indicating reduced ion migration and build-up by passivating the flaws on the perovskite surface. The champion device kept 95% of its preliminary effectiveness after 900 hrs, while the reference cell preserved only 49%.

The unique alignment of the o-OMe-PEAI on the 3D perovskite surface area disclosed greater hydrophobicity compared with various other salts, which in turn mirrored the higher security of the resulting gadgets.