Researchers in Finland are claiming a form of solar cells that can be applied to surfaces as a coat of paint could herald the future of solar energy.
Researchers at the University of Turku predict that dye-sensitized solar cells (DSCs) are set to become a ubiquitous source of energy. Research into such cells began in the 1990s. Now these Finn scientists say that the DCSs, which are inexpensive to produce compared to the complex and expensive clean-room manufacturing processes associated with current silicon-based solar panels, could help make solar power more accessible by driving down costs.
Solar energy developers have been looking for new ways to make photovoltaic cells (PV) for some years, mainly because of the high volumes of silicon needed to produce these first generation of solar energy capture devices. Research has ushered in second generation of solar cells made from multi-crystalline silicon, amorphous silicon, cadmium-telluride, and copper-indium-gallium-selenide.
The DSCs belong to the third generation. They are made from titanium oxide, a naturally occurring oxide. Used in various applications, such as pigments, the compound has also been applied as a photocatalyst and is widely used in semiconductors.
In the DSCs the oxide appears in the form of a white pigment. The pigment absorbs energy from the suns rays, which sucks electrons from dye molecules into a layer beneath the top coating. This movement of electrons creates a flow which produces an electrical current.
As well as their low cost, the DSCs have an extra advantage as a method of solar capture, which is that they can be applied to unconventional surfaces. Professor Michael Grätzel, who received the 2012 Albert Einstein World Award of Science for his work in developing the technology, has invented a method by which DSCs can be applied to surfaces as a coating of colored paint.
The Interdisciplinary Committee of the World Cultural Council awarded the prize to the professor for his Grätzel Cell invention, claiming that “chemistry for energy is currently one of the most important research topics for the future of our society and for mankind worldwide.”
The cells can be attached in the form of a spray or a paste to multiple surfaces, and could theoretically even be sprayed on to transport such as cars, trains, and buses.
Writing in the International Journal of Technology, Policy and Management this month, Jongyun Moon and his colleagues Aulis Tuominen and Arho Suominen at the University of Turku said that DSCs were still deficient in their ability to convert solar radiation into energy in comparison to more mature technologies. However, even with the low energy conversion rates DSCs are still being widely considered mainly, as Moon said, because of the low manufacturing cost associated with their production.
Writing in the paper Moon said: “It is, however unclear when DSCs could produce energy cost efficiently. As such, analysis on to what extent DSC technology could substitute for existing, more mature technologies is a challenging forecast.”