The prospect of cheap, reliable and efficient solar energy is still considered by many to be the holy grail of renewable energy to power homes and businesses. Researchers at Georgia Tech have developed a solar cell that improves efficiency by ‘growing’ carbon nanotube towers that create provide three-dimensional structure for the solar reactive compound cadmium telluride. The cadmium can then absorb photons striking the cells from a wide range of directions. This animation shows how the technology also improves efficiency by absorbing photons from light bouncing around between the carbon nanotube towers.

From the press release:

The new 3D solar cells capture photons from sunlight using an array of miniature “tower” structures that resemble high-rise buildings in a city street grid. The cells could find near-term applications for powering spacecraft, and by enabling efficiency improvements in photovoltaic coating materials, could also change the way solar cells are designed for a broad range of applications.

“Our goal is to harvest every last photon that is available to our cells,” said Jud Ready, a senior research engineer in the Electro-Optical Systems Laboratory at the Georgia Tech Research Institute (GTRI). “By capturing more of the light in our 3D structures, we can use much smaller photovoltaic arrays. On a satellite or other spacecraft, that would mean less weight and less space taken up with the PV system.”

(via Green Options)