Inkjet Printing: The Future Of Solar Cells?
Sometimes included as part of “all-in-one” machines, inkjet printers are used to perform tasks such as printing documents and photos and making copies. However, a recent discovery shows the versatility of inkjet technology: it can be used to create solar cells.
Engineers at Oregon State University have found a way to produce chalcopyrite, or “CIGS”, solar cells using inkjet technology. Engineers claim this new method is quicker, lowers the costs of producing solar cells, and yields 90% less raw materials wasted than traditional manufacturing methods, making a more cost-effective and environmentally friendly type of solar cell.
Very similar to how home and office inkjet printers work, engineers at OSU were able to print a chalcopyrite compound (the “ink”) directly onto a substrate (the “paper”) using inkjet technology. After trying different compounds, engineers produced an ink that yields about 5% solar efficiency. With continued research, they believe they can develop a “commercially-viable” ink with at least 12% solar efficiency.
“This is very promising and could be an important new technology to add to the solar energy field” says Chih-hung Chang, professor at OSU’s School of Chemical, Biological, and Environmental Engineering. Using inkjet technology to create chalcopyrite cells is an appealing alternative to the more traditional method of vapor phase deposition, which uses more expensive equipment and wastes more raw material. Professor Chang says inkjet technology makes it possible for the raw material to be printed precisely onto the substrate. This produces almost no wasted raw material, and especially as expensive some materials such as indium are, the cost to manufacture cells are significantly decreased.
Greg Herman, an associate professor of chemical engineering at OSU, is collaborating with the engineers to develop ink compounds that are even less expensive to make. Scientists also say producing solar cells using inkjet technology is less time consuming than traditional methods.
Chalcopyrite, also known as CIGS, consists of copper, indium, gallium, and selenium. Currently being studied and researched extensively, chalcopyrite has a much greater solar efficiency than silicon. A layer of chalcopyrite has the efficiency of a layer of silicon 25 to 50 times thicker. Clunky and obtrusive silicon solar panels may soon be a thing of the past.
Scientists believe inkjet technology will allow solar cells to be incorporated directly into various applications, such as roofing, windows, or curtains. As some may consider silicon solar panels unsightly, chalcopyrite cells can provide solar energy in a less conspicuous manner. Also, scientists believe, to satisfy the need to design and produce these new applications, new jobs could be created.
In the past, inkjet technology has been used in the production of solar cells. For example, silicon solar cells contain an arrangement of silver lines that carries electrical current. The traditional method of printing these lines is screen printing. However, scientists at the National Renewable Energy Laboratory (NREL) were able to formulate an ink that was more conductive than the silver paste used in screen printing. Additionally, the lines produced with inkjet technology were thinner than lines that were screen printed. Although less silver was used using the inkjet method, it was as energy efficient as the traditional method.
In 2008, Konarka Technologies used a FUJIFILM Dimatix Materials Printer to create photovoltaic solar cells. The company demonstrated that using inkjet technology, solar cells can be created without wasting raw material. The printer featured a cartridge that can be filled by scientists with their choice of ink.
Solar energy is regarded as a very clean and sustainable form of energy; however, many people overlook the environmental impacts and costs of manufacturing solar cells. If less wasteful and less expensive technologies, such as inkjet printing, can be implemented effectively in manufacturing solar cells, solar energy can be even more environmentally friendly and cost-effective.
Photo credit: flickr.com/photos/solar_decathlon/4009120815/