Oregon State University has printed a working CIGS thin film solar cell with inkjet technologies and safe, stable solutions. The team hopes to bring the inkjet CIGS photovoltaic efficiency up to 12%.
June 28, 2011 — Oregon State University engineers used inkjet printing technology to deposit thin films onto a substrate, creating a copper/indium/gallium/di-selenide (CIGS or chalcopyrite) thin film solar cell with 5% efficiency. Despite the low efficiency, which can be improved with further work, the research is heralded as a way to reduce materials waste by 90% during thin film deposition.
|This scanning electron microscope cross-sectional image shows the various compounds of a new chalcopyrite solar cell only a few microns thick, which can be created much less expensively with inkjet printing. (Image courtesy of Oregon State University)|
This is the first working CIGS solar cell printed with inkjet technology, said Chih-hung Chang, an OSU professor in the School of Chemical, Biological and Environmental Engineering. It is an alternative to vapor phase deposition, which requires expensive equipment and wastes a huge portion of raw materials, Chang added.
Inks that are “safe, cheap, and air-stable” can be made easily by “controlling the composition of low-cost metal salt precursors at a molecular level,” the researchers report.
Should the direct-write approach be improved and costs kept low, solar cells could be printed directly onto materials such as roofing shingles or curtains. Researchers hope to get solar cell efficiencies in the 12% range.
The findings have been published in Solar Energy Materials and Solar Cells and a patent applied for on the discovery.
In related work, being done in collaboration with Greg Herman, an OSU associate professor of chemical engineering, the engineers are studying other compounds that might also be used with inkjet technology, and cost even less.
The research was supported by the Daegu Gyeongbuk Institute of Science and Technology, the U.S. Department of Energy and OSU?s University Venture Development Fund.