Researchers at the University of Minnesota are developing Conductive Paint for Flexible Solar Panels
Researchers at the Materials Research Science and Engineering Center (MRSEC) at the University of Minnesota are developing conductive paint for making flexible solar panels. Efficient, flexible solar panels will be important for wide-scale use of solar energy. Silicon is the most commonly used material in electronic devices and solar cells. At present, silicon is used in the form of wafers, mechanically cut from block-cast silicon ingots. Another common form of silicon is an amorphous (noncrystalline) material deposited as a thin film onto plastic or glass using vacuum processes. For solar cells the cost of these forms of silicon is extremely high. Scientists have developed a simple approach to produce an ink of silicon that can be printed onto flexible substrates. The printing process is similar to that of an inkjet printer. The key to these inks is a process that makes silicon nanocrystals dispersed in an appropriate liquid base. When the ink is applied and the liquid base evaporates, a thin, conducting film of silicon remains. Usually, the preparation of such inks requires additives to help make a homogenous ink. However, these additives can also reduce the electrical conductivity and decrease the performance of the ink. The process used to make silicon inks is completed in a fraction of a second. The silicon nanocrystals are soluble in organic solvents, such as alcohols and hydrocarbons, and the ink is readily used in a variety of printing processes. This technology is a significant breakthrough in developing low-cost, flexible solar cells.