The low temperature of the silicon chip in this process means that it could be combined with other materials, such as organic compounds or polymers, that would be destroyed by the higher temperature of the conventional coating process. This could enable new applications of silicon chips for example, as biosensors following bonding with compounds that react with specific biological molecules. "People have grafted DNA and protein antibodies to silicon," Yang notes.
The energy used in manufacturing silicon solar cells is a critical concern because every bit of cost savings helps to make them more competitive with other sources of electricity. The lower temperatures could significantly reduce manufacturing costs, the MIT researchers say.
The new process also has an added benefit, providing an anti-reflective coating that improves a solar cell's overall efficiency, the team says.
Both the conventional process and the new process take place in a vacuum chamber. Liquid reactants evaporate, then adsorb and react on the surface. The adsorption step is much the same as mist forming on a cold bathroom window after you take a shower.
The process can easily be scaled to the size of conventional solar cells, Gleason says. Additionally, the materials involved are all commercially available, so implementing the new method for commercial production could be a relatively quick process.
Buonassisi describes lowering the cost of manufacturing equipment, including that used to apply the passivating and antireflection coating, as "one of the three steps that's needed to drive down the price of solar modules to widespread grid competitiveness." (The other two are improvements in efficiency and reducing the amount of materi
|Contact: Sarah McDonnell|
Massachusetts Institute of Technology