New Film Converts Low-energy Light to High-energy Light
Expected applications include solar cells, windows
Industrial Technology Center of Wakayama Prefecture (WINTEC) announced Jan 8, 2019, that it has developed a "light upconversion film" capable of stably converting low-energy light (long-wavelength light) to high-energy light (short-wavelength light) in the air and obtained a patent for it.
There has already been a pigment that causes "light upconversion phenomenon." But it deteriorates due to oxygen, water vapor, etc. So, the phenomenon occurs only when the pigment does not contact air (e.g. crystal and solution (semisolid)), making commercialization difficult.
This time, WINTEC confined the pigment to a polyvinyl alcohol film and extended the film by using its own technology to mitigates the deterioration of the pigment.
WINTEC used the prototyped film and succeeded in converting green light to blue light. This technology can be applied to a large area, and the film can be easily formed in the atmosphere. On the other hand, it is still in the basic research stage, and the conversion efficiency is low.
For the future, the film is expected to (1) be attached to solar cells to improve their power generation efficiencies, (2) be attached to windows to improve energy-saving performance and increase the amount of light and (3) replace paper for paper currencies, etc to prevent counterfeiting. WINTEC will seek a joint research with companies based in Wakayama Prefecture and make efforts to understand the light-emitting mechanism and build up knowhow.