Hokkaido University announced Oct 8, 2015, that it has applied the "Chameleon Luminophore" technology, which changes the color of emitted light in accordance with temperature changes, to a crystalline silicon (Si) solar cell and improved its conversion efficiency by 2%.
It is an achievement made by Yasuchika Hasegawa (professor, Faculty of Engineering, Graduate School, Hokkaido University), and the increase of 2% is a world record, according to the university.
The Chameleon Luminophore is a molecule-type luminous body containing europium (rare earth), and Hokkaido University announced it in May 2013. This time, Hasegawa added a Chameleon Luminophore derivative capable of efficiently converting ultraviolet light into red light to a special film (EVA film) to be attached to a conventional crystalline Si solar panel.
When the film is attached to the surface of a solar panel, the Chameleon Luminophore absorbs ultraviolet light and emits light whose color falls into the red color region, increasing the light-absorbing region of the crystalline Si solar cell and, thus, conversion efficiency by 2%.
The film can be attached to crystalline Si solar panels, which are widely used across the globe. Based on the results of a durability test, the film's effect of increasing conversion efficiency is considered to be valid for 10 years. Therefore, there are high hopes that the film will be used as a practical part for improving crystalline Si solar cells, according to the university.