Researchers at Ohio State University have created a new material that overcomes two of the major obstacles to solar power: it absorbs all the energy contained in sunlight, and it generates electrons in a way that makes them easier to capture. The new hybrid material was created by combining electrically conductive plastic with metals including molybdenum and titanium. "There are other such hybrids out there," explained Malcolm Chisholm, Distinguished University Professor and Chair of the Department of Chemistry at Ohio State, "but the advantage of our material is that we can cover the entire range of the solar spectrum."
Sunlight contains the entire spectrum of colors that can be seen with the naked eye. What our eyes interpret as color are really different energy levels, or frequencies of light. The problem with today's solar cell materials is that they can only capture a small range of frequencies, so they can only capture a small fraction of the energy contained in sunlight. This new material is the first that can absorb all the energy contained in visible light at once.
The new material generates electricity just like other solar cell materials do; i.e. light energizes the atoms of the material, and some of the electrons in those atoms are knocked loose. Ideally, those electrons flow out of the device as electrical current, but this is where most solar cells run into trouble. The electrons only stay loose for a tiny fraction of a second before they sink back into the atoms from which they came. In the new hybrid material, electrons remain free much longer than they ever have before. Although the material is years from commercial development, the researchers say this experiment provides proof that hybrid solar cell materials can offer unusual properties.
