Solar cells as art

Sure, solar panels are nice if you just want nonpolluting renewable energy. But what if you want to add a designer touch to your building? You can’t expect the fashion conscious home owner to be satisfied with plain black solar panels on their roof.

I might interject here to say that I have plain black solar panels on my roof, and I’m totally satisfied. But on with the story.
 
University of Michigan researchers led by Jae Yong Lee have found a way to make colored photovoltaic cells. The prototypes are able to convert 2% of the sun’s energy into usable energy. That's quite a bit worse than the 10% efficiency achieved by the top of the line solar cells. But those cells don’t have pretty pictures on them.

Professon Jay Guo holds up a prototype.
Image courtesy of University of Michigan

The colors on the solar cells aren’t pigments, but rather are created by varying the thickness of the silicon within the cells. Blue areas are six nanometers thick, whereas red areas are 31 nanometers thick. This means that the colors are not dependent on the viewing angle. The different structures capture and transmit different wavelengths of light.

Lead author Jay Guo explains:

Lee, J., Lee, K., Seo, S., & Guo, L. (2014). Decorative power generating panels creating angle insensitive transmissive colors Scientific Reports, 4 DOI: 10.1038/srep04192.