California startup BioSolar, Inc. (BioSolar) has a different focus than most companies in the solar industry. Instead of building better ways to absorb the sun’s rays and convert the light into energy, BioSolar develops cheaper and more environmentally-friendly protective backing for solar cells.
Currently, the vast majority of protective backsheets for solar cells are made by DuPont from a petroleum-based film called Tedlar. BioSolar’s backing is made from bio-based materials.
BioSolar has a patent application directed to a process for building solar cells using a bio-based plastic substrate. U.S. Application Pub. No. 2007/0295394 (‘394 application) seeks to overcome the primary problems associated with bio-based materials in solar applications – their relatively low melting points and de-gasing temperature points.
The keys to the process disclosed in the ‘394 application are de-gasing the substrate material at a temperature of 120 degrees so the material maintains its shape without bubbling or cracking and applying a silicon oxide barrier layer to seal the potential micro-cracks and stabilize the substrate for its journey through the remainder of the solar cell production process.
According to this green tech media piece, BioSolar has not disclosed which bio-materials are used to make the substrate. Â
The ‘394 application offers one possibility:  the application states that the bio-based substrate “is made from Poly Lactic Acid (PLA); a material generated from corn dextrose…”Â
