The crystalline silicon in solar panels is salted with atomic-scale impurities such as boron or phosphorus to boost its conductivity. Now engineers at the Lawrence Berkeley National Laboratory have found a way to make solar cells just as efficient without this added step of “doping.” The resulting cost savings can make solar electricity even cheaper.
Instead of adding foreign elements into the silicon, the process overlays the crystal silicon with a coating of lithium fluoride covered by a film of molybdenum oxide. The molybdenum absorbs sunlight; the lithium transfers electrons to the silicon.
The two materials complement each other’s electrical properties, making the transfer of electrons particularly efficient. The two coatings can be applied at room temperatures, reducing manufacturing costs.
TRENDPOST: Incremental improvements in photovoltaic electricity technology will continue to boost performance efficiency and chip away at costs. Big breakthroughs will be rare. Investors will do best with existing companies that have robust tech-development operations.