Transparent Electronics: A Solar Energy Breakthrough
Not even in our wildest dreams have we anticipated that while we are simply looking out the window enjoying the outside view our windows can simultaneously produce energy for our household needs! Not only windows but the facade of the house, too, might be harnessing the power of solar energy. This might be our future domestic power supply scenario. This can be possible with the help of transparent solar cells. These solar cells can increase the surface area to produce energy.
Researchers in Germany have taken help of advanced physics models to develop transparent materials that could act as solar cells. The team from Fraunhofer Institute for Mechanics of Materials (IWM) is developing transparent base materials that could be doped with atoms to attain conductive coatings. The transparent base requires one coating to conduct the electricity via electrons. That will be acknowledged as the n-conductors. They will need another coating in which electron holes facilitate the electricity to flow, known as the p-conductors.
But the IWM team is facing few hurdles. While n-conducting transparent materials are easily available for their work, they are facing some problems with p-conducting materials. First problem is their conductivity that is too low and the second difficulty is their transparency that is poor. So manufacturers have to find a transparent material that gels well with both n and p doping.
Wolfgang Körner, who is the research scientist at the IWM, said: “If transparent p-conductors with adequate conductivity could be produced, it would be possible to realize completely transparent electronics.”
Researchers are utilizing indium tin oxide for the n-conductors, but the hitch is that this is costly. Indium is considered an extraordinary commodity and it has reported a tenfold increase in price since 2002. We know that for commercial success of transparent solar cells they have to use cheaper materials. Therefore the research team is looking for alternatives. The team has to confront other questions too, such as best suitable material, what they should be doped with to acquire first-rate conductivity, and how high-quality their transparency is. Researchers are trying to find out the grain boundaries i.e. irregularities in the ordered crystal structure. They have a herculean task ahead of them because they want to duplicate these defect structures atom by atom. Special replication methods compute how the electrons are distributed in the structures and thus in the solid body. From the data the researchers will determine how conductive and transparent the material is. Körner said, “We have found, for example, that phosphorus is suitable for p-doping zinc oxide, but that nitrogen is more promising.”