Georgia Tech has developed a PV cell with a three dimensional structure that captures nearly all the light illuminating its surface.
Unique three-dimensional solar cells that capture nearly all of the light that strikes them could boost the efficiency of photovoltaic (PV) systems while reducing their size, weight, and mechanical complexity.
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.
The ability of the 3D cells to absorb virtually all of the light that strikes them could also enable improvements in the efficiency with which the cells convert the photons they absorb into electrical current.
Being able to capture all of the light can be a major leap in the use of solar cells. At present, photovoltaics are sensitive to only one portion of the light spectrum, usually green, while efficiencies fall off on either side, meaning that the solar cells don't easily convert light from either the red or blue part of the visible spectrum into electricity. Much of it either passes through or is reflected by the cell. Being able to capture all of the light striking the cell means being able to convert almost all of it into electricity.
If this cell can be made in commercial quantities at a low enough price and the conversion efficiencies are as high as the developers believe they can be, then photovoltaic cells may come to the forefront of alternative energy sources.