Author, Institution: Artiom Magomedov, Kaunas University of Technology
Science area, field of science: Natural Sciences, Chemistry N003
Scientific Supervisor: Prof. dr. Vytautas Getautis (Kaunas University of Technology, Natural Sciences, Chemistry, N003).
Dissertation Defence Board of Chemistry Science Field:
Prof. Dr. Saulius Grigalevičius (Kaunas University of Technology, Natural Sciences, Chemistry, N003), chairman
Prof. Dr. Habil. Vidmantas Gulbinas (Center for Physical Sciences and Technology, Natural Sciences, Physics, N002);
Prof. Dr. Vytas Martynaitis (Kaunas University of Technology, Natural Sciences, Chemistry, N003);
Prof. Dr. Edvinas Orentas (Vilnius University, Natural Sciences, Chemistry, N003);
Dr. Wolfgang Tress (Ludwig Maximilian University of Munich, Germany, Natural Sciences, Physics, N002).
The doctoral dissertation is available on the internet and and at the library of Kaunas University of Technology (K. Donelaičio St. 20, Kaunas, Lithuania).
Perovskite solar cells currently is the fastest developing technology for the solar energy harvesting. Their progress is strongly dependent on the used organic materials, in particular hole-transporting materials (HTMs). In the scope of this dissertation, several issues related to HTMs are addressed, i.e., efficient synthesis, doping-induced degradation, and the alternative layer formation method. First, a simple synthetical pathway which leads to HTMs with a stable amorphous phase was developed. It was further adapted to the synthesis of carbazole-based HTMs, which shoved good performance in perovskite solar cells. Next, another parameter, long-term stability, which is important for successful commercial application, was addressed. Due to their low conductivity in the pristine state, HTMs are used in a combination with several dopants. It was shown that oxidized HTM species undergo a chemical reaction with 4-tert-butylpyridine (tBP), and novel species are formed. Finally, seeking for a way to exclude dopants from the HTM composition, a novel layer formation procedure was proposed, utilizing self-assembly on indium tin oxide substrate. The devices made with such layers have shown a very promising efficiency of 17.8% thus making this alternative approach attractive for further development. In conclusion, this work presents a significant improvement in the field of HTMs for perovskite solar cells by setting a new pathway for the development of functional materials.