With solar power becoming more and more popular in today’s society, scientists are racing to find new ways to make the conversion of solar light into usable energy cheaper to manufacture and more efficient.
Currently solar panels are made by cutting crystalline silicon into really small disks less than a centimeter thick. These small thin disks are meticulously polished and treated to repair any damage caused by the cutting process. After polishing, metal conductors and dopants (materials added to alter the electrical charge in the photovoltaic solar cell) are spread across each disk. The disks are arranged in a grid-like pattern on the top of the solar panel. The panel is then covered with a protective sheet of thin glass that is bonded to the panel. It is then bonded to a base material with a very expensive thermal cement. The cement is needed to help channel excess heat away from the panel, so as to not overheat the cells. Although, these panels work, they are not as efficient as most researchers would like. They are also fairly expensive and still have a tendency to over-heat.
David Ginger, an associate professor of chemistry at the University of Washington and his team of researchers think they may have found the answer. They found a way to create images of super tiny bubbles and channels (apoximately 10,000 times smaller than a human hair ) inside organic plastic solar cells. It turns out that if the plastic polymers are spread thin and baked, the bubbles and channels will form as a natural consequence of the heating process. The intensity and duration o the heat affects the configuration of the bubbles. The configuration or the bubbles dictates the efficiency of the solar cell.
Paul Berger, professor of electrical and computer engineering and professor of physics at Ohio State has been expanding on the use of plastic polymers to capture and convert solar light into efficient energy. Berger and his team found that adding tiny silver nanoparticles to the plastic polymers increased the efficiency of the solar panels (electrical current generated per square centimeter) increased by almost 12%. “The small silver particles help the polymer capture a wider range of wavelengths of sunlight than would normally be possible, which in turn increases the current output,” Berger explained.
Meanwhile, Brian Korgel, a chemical engineer at the University of Texas is working on a solar “ink”. These nanoparticle solar inks can be printed on a plastic substrate or on stainless steel. Conceivably, they could be painted directly onto roofs or the sides of buildings. Korgel and his team are hoping that this technology can cut the cost of production of solar cells to 1/10th of what it is today!
As our society focuses more and more on “green energy” solutions, the demand for research into more efficient solar technology grows. It is the common hope that with the advancement of these technologies, the utilization of solar energy will become economically viable enough to someday completely replace fossil fuels.