Room temperature slot-die coated perovskite layer modified with sulfonyl-γ-AApeptide for high performance perovskite solar devices
Perovskite solar cells (PSCs) exhibited remarkable progress for small aperture area cells, however, the performance of its counterpart, large aperture area cells, lags due to non-uniform and defective perovskite layers. Here, we fabricate reproducible large area homogeneous perovskite films at room temperature and without controlling humidity (up to 40 % RH) with a slot die coater on a c-TiO 2 layer deposited using a large area chemical bath. A new artificial peptide – sulfonyl-γ-AApeptide (F-GLU-S) was employed to modify the slot-die coated perovskite surface, grain boundaries and electronic defects. The multi-functional F-GLU-S with carbonyl, carboxyl, sulfonyl, benzene, and chloro groups was capable of strongly interacting with the perovskite layer and repairing the uncoordinated Pb 2+ ions and halide vacancies. As a result, both the electron and hole densities of defects were significantly suppressed; consequently, the non-radiative recombination was effectively suppressed for the modified device which can be explicitly seen in the device performance where both V oc and FF of the modified device improved considerably. Therefore, F-GLU-S modified slot-die coated MAPbI 3 – based devices demonstrated outstanding performance of 21.44 % PCE with a V oc of 1.13 V, J sc of 24.64 cm –2 , and FF 76.99 %. Furthermore, F-GLU-S passivation impeded the infiltration of moisture and oxygen due to its hydrophobic nature and defect repair potential. As a result, the modified device retained above 92 % of its original PCE after 720 h in air (room temperature and 40–60 % RH).