| Abstract [eng] |
In the near future, the global energy demand is likely to surpass the capacity of fossil fuel-based energy sources. As a result, there is an increasing emphasis on the use of renewable energy sources and development of technologies that can convert these sources into electricity. Solar energy provides an inexhaustible source of energy that can meet the growing demand. Solar cells are being used to harness the power of the sun. The third-generation solar cells, called perovskite solar cells, have emerged as a viable competitor to silicon solar cells due to their increasing efficiency. The hole-transporting material plays a crucial role as the main component in perovskite solar cells, affecting the price, efficiency and stability of the device. Currently, the highest efficiency of perovskite solar cells has been achieved with spiro-OMeTAD as the hole-transporting material. However, spiro-OMeTAD has several disadvantages, including the complex and expensive synthesis, as well as the crystallization tendency of its molecules, resulting in degradation of hole-transporting layer and device stability. To address this problem, axial helix derivatives of triphenylethene have emerged as a promising alternative. The aim of this work was to synthesize organic semiconductors with a central triphenylethene fragment, investigate the properties of these compounds and use them as hole-transporting materials in perovskite solar cells. In this work, eight triphenylethene derivatives 5, 7, 11–13, and 19–21 with fluorenyl or carbazolyl chromophores were synthesized through simple synthesis methodologies. The chemical structures of the new semiconductors were confirmed by mass spectrometry, 1H NMR, 13C NMR and elemental analysis data. The numerical values of ionization potential (IPEF) of new compounds 5, 7, 11–13, and 19–21 are distributed in the interval from 5.05 eV to 5.41 eV, and the determined hole drift mobility values are µ(0) = 2.1·10-6–4.6·10-5 cm2/Vs. The obtained investigation results have confirmed the suitability of these semiconductors for application in perovskite solar cells. The energy conversion efficiency of solar cells with triphenylethene derivatives 11–13 and 19–21 bearing fluorenyl chromophores as hole-transporting materials did not exceed 14% because of the higher ionization potential values of the compounds, while the energy conversion efficiency of the devices with semiconductors 5 and 7 bearing carbazolyl chromophores exceeded even 21%. The highest efficiency of 23.43% was achieved in the device employing semiconductor 7, though it was lower than that of the spiro-OMeTAD benchmark (PCE = 24.81%). However, the stability of the solar cell with hole-transporting material 7 was significantly greater. |
