We begin by growing a thin layer of GaAs on top of a single crystal GaAs wafer using a high throughput metalorganic chemical vapor deposition (MOCVD) process. We then remove this thin layer via an epitaxial lift-off (ELO) process which leaves a thin, flexible, and lightweight solar cell.
The backbone of our entire technology is gallium arsenide (GaAs) which is a III-V semiconductor with a Zinc Blende crystal structure. GaAs solar cells were first developed in the early 1970s and have several unique advantages. GaAs is naturally robust to moisture and UV radiation making it very durable. It has a wide and direct band gap which allows for more efficient photon absorption and high output power density. Finally, it has a low temperature coefficient and strong low light performance.
Alta Devices houses three unique tools that allow for the mass production of thin film GaAs.
In addition to being a direct band gap material, we are able to achieve our record breaking efficiencies through the observed phenomenon called “Photon Recycling”. In this process photons bounce off the back of the solar cell which allows them to be recaptured by the material and converted to electricity. Thus, more energy is captured where it would have been lost using traditional solar technology.
Watch this short video to learn the basics of solar energy, how it is converted into usable electricity, and what sets Alta’s cells apart from others on the market.
December 27, 2012
Watch this short video to learn how Alta breaks records with their thin-film solar cells, what these cells allow them to do that other solar cells can not, and how Alta achieves such results.
December 27, 2012
