Scientists are using sensitized solar cells as a low-cost complement to current photovoltaic systems. However, researchers have been looking for some environmentally friendly and environmentally friendly materials that improve performance and thus fulfill their promise.
Now, a team of researchers at the University of Basel in Switzerland has found a way to develop a sensitizer, a very critical element in batteries, from a common metal iron with minimal environmental impact. A sensitizer is an intensely colored compound that absorbs light and converts its energy into electricity by releasing electrons and 'injecting' them into a semiconductor.
Although researchers already know a good basis for developing sensitizers for iron, they still need to overcome some challenges to achieve this goal. In fact, experts have long believed that the use of iron compounds in these applications is impossible because the iron compounds have too short lifetimes in the struck state after light absorption and may not be useful for energy production.
As a result, the sensitizers used until now to sensitize solar cells either have relatively short lifetimes or require the use of very rare and expensive metals, the researchers say.
However, seven years ago, researchers developed a new class of iron compounds, dubbed N-heterocyclic carbenes (NHCs), that can prolong the state required for semiconductors to release enough electrons to generate electricity.
This solves one problem of using iron as a sensitizer; however, there are still other problems to be solved in the process of sensitizing semiconductor surfaces with dyes, which are affected by the nature of the dye molecules, the impregnation of the electrodes The effect of the solvent of the liquid and the time of sensitization, the researchers observed in the abstract of a paper published in the journal Dalton Transactions.
"If dye molecules are too close together, dye-to-dye interactions may affect charge properties," the researchers wrote. "Dye aggregation is the result of intermolecular interactions. This limitation can be achieved by adding co-adsorbents, For example, chenodeoxycholic or the use of alkyl spacers in the dye structure to overcome."
The researchers also wrote that another problem may arise from the presence of too many dye molecules in the dye bath solution, leading to the formation of multilayer films on the semiconductor surface. In this case, the dye bath concentration and soaking time must be optimized.
Taking into account the many factors that influence the process, Mariia Becker, project leader at the University's Department of Chemistry, explains: "We knew we had to develop materials that could attach to semiconductor surfaces and whose properties would at the same time allow optimization of the functionality on the surface. Arrangement of light-absorbing components.”
The potential of batteries of the future
To address these challenges, the researchers developed a new sensitizer by using new homogeneous and heterogeneous iron NHC materials, which they created using a two-pronged approach, they said.
First, they added carboxylic acid groups, such as those found in vinegar, to the iron compound, allowing it to bind to the semiconductor surface. Second, they made the resulting compound more 'silky' by adding long carbon chains to make the surface layer more fluid and easier to set.
Overall, the study shows the possibilities created by using iron in fuel-sensitized solar cells, and the researchers have a long way to go, as their prototype achieves only 1 percent of the overall efficiency. By comparison, commercial solar cells have an efficiency of 20 percent.
"Nevertheless, this result represents a milestone that will encourage further research into these new materials," Becker said in a press release.