Costs of silicon based solar cells have made scientists develop different technologies which should be easily affordable and efficient. A San Jose, California based company called Solexant has started the development of a thin film solar cell which is cheap and very efficient. Solexant is very confident that their serial production thin film solar cell will have an efficiency increase of 10% compared to silicon based solar cells. This will be a real breakthrough as it is known that thin film cells usually have low efficiency. The cost reduction of this thin film cell comes from the fact that Solexant uses a roll-to-roll printing process. The technology licensed from the University of California’s Professor Paul Alivisatos uses a nanoparticle ink which is printed on a metal film substrate. The ink is made of 20-30 nanometer long rod-shaped semi-conducting nanocrystals and also other components which were not divulged by the company.
But things are not so easy at this moment and developments still need to fix some bugs. The problems come mainly from the nanocrystals, as the electrons tend to get trapped in between the particles. According to MIT’s Technology Review, the rods are merely the primary structures of the nanocrystals. When the ink is printed the substrate is heated. While heated, the nanocrystals fuse and form larger crystals that do not trap electrons.
But Solexant is very confident that they will solve the actual issue until next year when they hope to have their $1 per watt solar cell with a single layer of nanocrystals on the market. The goal is to make a multilayer broad-spectrum solar cell in the near future. By next year, their pilot plant will be up and running with a $22.5 million venture funding granted to the company.