Developing Transparent Solar Panels for Windows

Scientists at the University of Tokyo have made new progress in developing solar cells that can cover windows without obstructing views.

Currently, the typical black solar panels seen on rooftops rely on silicon to absorb light across a wide spectrum of wavelengths. In an attempt to create efficient, transparent solar panels, the researchers' work led them to revisit two existing technologies. The result was a transparent solar cell with greater efficiency than previously achieved. 

Coupling two known technologies

With the understanding that green light is the main priority for visibility, the researchers focused on developing a cell that mostly absorbed red and blue light, while allowing green light to pass through. They turned to perovskite to create transparent cells.

Perovskites have been used previously but the issue was that earlier attempts resulted in cells that weren’t able to create sufficient power to be practical. To change this, the researchers relied on silver nanotubes.

Silver nanotubes have also been used in solar cells to increase the efficiency of light-capturing, but a new technique was able to produce greater efficiency. The aim here was to use the silver to target red wavelengths that the perovskite couldn’t absorb. The researchers were able to effectively capture these red wavelengths by coupling the effects of the nanotubes with the cell’s other electrode layer, also made of silver. Doing so encouraged the plasmic antenna effect, which increased the cell’s light absorption ability and thus its efficiency.

To learn more about this technology, see the published findings in the open-access article in Scientific Reports