Novel Solar Cell Materials

There are following categories (projects and possibly other research subjects) related to Novel Solar Cell Materials:

• Polymer Solar Cells
• Dye-sensitized Solar Cells
• Transport in organic solar-cell materials studied by time-resolved terahertz spectroscopy

The total annual global energy consumption is predicted to at least double from its current level of 14 TW by 2050. Fossil fuels that today account for 80 % of the consumption will not supply the future need because of dwindling sources and unacceptable environmental effects by increasing levels of carbon dioxide. Solar energy, however, is plentiful - in one hour the Earth receives from the sun enough energy to meet the world's annual needs. The problem lies in harnessing it. Photosynthesis is Nature's way to harvesting solar energy and it has been perfected through the billion of years. For artificial solar energy conversion one can think of two possibilities - mimicking photosynthesis to produce energy rich molecules or converting light to electricity. In this part of our research we are studying the properties and processes of novel solar cell materials with the aim to provide new knowledge that can be used to develop new and improved materials. Our work is conducted in collaboration with other scientists for material and device development.

Figure 1. Each red squares illustrate the surface area needed to collect 3.3 TW with a solar cell. Thus, all six boxes would cover the predicted increase in energy consumption by year 2050. If solar cells are placed on the roofs and facades of buildings this will bring us a long way.

We are working with two different types of novel solar cells.

Dye sensitized solar cells in which the active material is a thin film of semiconductor (i.e. TiO2 or ZnO) nanoparticles sensitized by dye molecules to harvest as much as possible of the solar spectrum.

Plastic solar cells in which the active material is a thin nanostructured film of an organic semiconductor, often a blend of a conjugated polymer and a fullerene derivative.