In this thesis, we focused on the influence of different antisolvents on the performance and stability of perovskite solar cells, which are considered one of the most promising alternatives to conventional silicon-based technologies. One of the key steps in the preparation process is the addition of an antisolvent during spin-coating, which strongly affects perovskite crystallization and thereby the quality of the active layer.
At the beginning, by varying the amount and deposition rate of the antisolvent, we determined the most optimal deposition conditions for four antisolvents (toluene, anisole, ethanol, and isopropanol). Based on these parameters, we later carried out several series on different perovskite compositions, in which the antisolvents were directly compared. The comparison included the four previously mentioned antisolvents, as well as ethyl acetate, which had served as a reference so far, and chlorobenzene.
The results showed that in the baseline composition (FACs 83:17, 1.63 eV bandgap), ethyl acetate achieved the highest efficiency (17.10%), while toluene provided the longest stability (280 h). In the composition with higher bromine content (FACs 60:40, 1.74 eV bandgap), isopropanol and anisole proved to be the most suitable, whereas in the bromine-free composition (FACs 100:0, 1.55 eV bandgap), the highest efficiency achieved was 17.35% with isopropanol. Photoluminescence measurements revealed significant differences in film quality. In the FACs 60:40 composition, ethanol and isopropanol showed markedly lower PLQY values, which was also reflected in inhomogeneous sample surfaces and a higher presence of defects. In contrast, chlorobenzene and ethyl acetate produced films with higher crystal lattice quality. In the bromine-free composition (FACs 100:0), ethyl acetate and toluene performed worse, while chlorobenzene and anisole achieved higher PLQY values and better optical properties.
Based on these findings, we can conclude that the choice of antisolvent represents a compromise between the efficiency and stability of perovskite solar cells. Future research should focus on developing more environmentally friendly antisolvents that enable both high efficiency and long-term operation.
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