| Abstract [eng] |
Over the last decade, renewable energy has attracted major interest. It is expected to reduce the consumption of fossil fuel and to make more energy from renewable sources. One of the most popular renewable sources is solar energy. Silicon solar cells are well-known, however, it is not only solar cell technology. One of the most researched technologies is perovskite solar cells, which efficiency reached more than 25 %. This is close result in comparison with silicon solar cells. One of the main reasons, why perovskite solar cells are not in the mass production yet is the stability-related issues. Solar cells are made of layers. The hole transporting material layer is often described as the weakest link of the perovskite solar cells, due to the extensive use of the dopants. Therefore, it is important to look for alternative, dopant-free hole transporting materials, that do not require the use of the dopants. Recently, as an alternative to the traditional hole-transporting materials, hole-selective monolayers were introduced. In this material, carbazole moiety is ensuring high selectivity for holes, while phosphonic acid anchoring group is providing good binding with indium tin oxide surface. In this work, a series of new carbazole-based phosphonic acids with different aliphatic chain linkers were synthesized. It is expected, that longer aliphatic chains could improve the ordering of the monolayer film, however, at the cost of reduced ability to transport charges. The synthesized materials were tested in photovoltaic devices. The result shows that longer linker reduces efficiency, while voltage remains similar. Moreover, changing the aliphatic linker to the phenyl ring in phosphonic acid structure does not improve efficiency. |
