PV polarizer technology lets cell phones charge themselves

An engineering team at the University of California–Los Angeles (UCLA) Henry Samueli School of Engineering and Applied Science has developed a polarizing organic photovoltaic (PV) layer for liquid-crystal displays (LCDs) that simultaneously acts as a polarizer and a PV device. The polarizing organic PV layer can potentially convert as much as 75% of the backlight photons that are typically lost by polarizer layers within an LCD into usable electricity. The thin-film material, which is created in a simple coating method in a large-area manufacturing process, can also be used as a conventional PV device to gather photons from sunlight.

The thin films are fabricated through the uniaxial orientation of polymer conjugated molecules; in this case, the polymer used is poly(3-hexylthiophene) or P3HT—the most popular p-type polymer in organic photovoltaic technology. The technology works as a PV device by harvesting the electromagnetic wave component parallel to the molecular chain orientation (p-mode polarized light) of the LCD, converting it into electricity. By rubbing P3HT film with a velvet cloth at 150°C, the polymeric molecules are oriented along the rubbing direction, creating a polarizing P3HT film with anisotropic optical properties. The work on this technology was supported by the Intel Labs Academic Research Office and the Office of Naval Research.

Contact Rui Zhu at [email protected].