October 10, 2003 – After recently revealing its efforts to develop silicon with better illuminative properties, STMicroelectronics has launched an R&D program to apply its nanotechnology expertise to the field of photovoltaics, i.e., solar-cell technology.
Photovoltaics works by absorbing sunlight and converting photons into electrons and holes, separating these with an electric field, and conducting them to contacts where they are collected. Solar-cell technology promises to produce far cleaner and efficient energy than fossil or nuclear fuels.
However, due to high materials costs, current photovoltaic technologies based on semiconductor materials such as silicon are up to ten times more expensive. STMicro’s goal is to develop new solar cells with lower efficiencies (10% of solar energy converted into electricity, instead of the ideal 15% to 20%) but also lower manufacturing costs.
“The ability to produce low-cost, high-efficiency solar cells would revolutionize the field of solar energy generation, allowing it to compete more effectively with fossil fuel sources,” according to Dr. Salvo Coffa, STMicro’s research group director.
To this end, the company is exploring two methods. The first is a solar cell made from high-purity silicon to perform all three solar cell processes. The other method will use an organic dye to absorb sunlight, a nanoporous metal oxide layer to transport electrons, and a liquid electrolyte to transport the holes.
STMicro is also developing cells using a mixture of organic materials, including fullerene and an organic copper compound, to create nanostructures with contacts at distances less than 10nm.