NREL and SLAC scientists uncover key to more cost effective and green solar cells
Scientists at SLAC National Accelerator Laboratory and the DOE’s National Renewable Energy Laboratory (NREL) announced on Friday the discovery of a key finding that could allow for more cost-effective and green solar cell production.
Silicon solar cells are created using a paste comprised of silver powder, glass frit and an organic binder. Current methodologies, however, are expensive and potentially harmful to the environment because silver is a precious metal, and lead oxide that is used in glass frit may contribute to greenhouse gas emissions.
To combat this, scientists have worked hard to discover the chemical process that takes place during the firing and binding manufacturing process so that alternative compounds can be found. Because the binding takes place in seconds, understanding the process has proved difficult, but NREL and SLAC scientists found a way.
By creating a rapid thermal processing instrument, the scientists were able to X-ray the contact formation process at intervals of 100-milliseconds and 100 degrees Celsius per second. This allowed researchers to discover that lead oxide might be responsible for the antireflective coating on solar cells, while silver might be the binding agent that sets the glass.
The scientists observed the process in the presence of various gases, including nitrogen and oxygen, and noted the properties of the substances changed. The research was highly successful and may result in the development of silicon cells using more eco-friendly and cost-effective substances.
