| Abstract [eng] |
Over the last few decades increased amounts of energy consumption directly affected the climate. Limited reserves of fossil fuels require more research on sustainable and renewable energy sources. One of the most attractive alternatives are photovoltaic systems, which use sunlight as free and endless energy source without additional depletion of Earth’s resources. Solar energy usage can provide opportunity to reduce CO2 emissions and mitigate the harmful effects of climate change. Perovskite solar cells are considered as promising candidates for next‐generation energy harvesting devices, due to their low cost, simple fabrication process and high power conversion efficiency (25.2 %). However, one of the biggest problems of these devices is long-term stability. For example, dopants, such as Li-TFSI and 4-tert-butylpyridine, are important additives which increase conductivity of hole transporting materials and power conversion efficiency of perovskite solar cells. Unfortunately, both dopants accelerate degradation of perovskite devices and reduce lifetime: Li-TFSI is hygroscopic, while 4-tert-butylpyridine has relative low boiling point and 4-tert-butylpyridine may form pyridinated derivatives. Fullerenes and their modified derivatives are widely used as n-type semiconductors in inverted perovskite solar cells. Nevertheless, solubility of non-modified fullerenes in organic solvents is low, while modified ones are rather expensive. These disadvantages limit applicability of fullerenes in perovskite solar cells. The aim of this work – to synthesize new n-type 1,4,5,8-naphtalenetetracarboxylic diimide semiconductors, containing pyridine, ammonium, or phosphonic acid anchoring groups and investigate their properties, applicability in perovskite solar cells. In this work new semiconductors 1, 3, 8, 10, containing 1,4,5,8,-naphtalenetetracarboxylic diimide central fragment and pyridine, ammonium, phosphonic acid, pentafluorphenyl and di-tert-butylphenyl functional groups were synthesized. Additionally, new symmetric diimide derivatives (11, 12, 13) and compound containing ammonium and sulfonic acid anchoring groups (4) were synthesized. Thermal, optical, photoelectrical properties of the synthesized compounds were investigated. Using electron transporting materials 1 and 10 perovskite solar cells were constructed and photovoltaic characteristics of these devices were measured. Studies have revealed that compounds 1, 3, 8, 10 can be used as n-type semiconductors in perovskite solar cells. Compound 3 with ammonium and pentafluorphenyl fragments formed hydrophobic layer on the surface of perovskite, which has improved moisture resistance of the perovskite. Additionally, using diimides 1 and 10 different monolayer forming procedures were tested, perovskite solar cells were constructed and their photovoltaic characteristics investigated. |
