Photovoltaic, Thin Film, Multijunction
Multijunction cells take advantage of multiple materials, each of which best capture a particular light wavelength (color spectrum) for solar to electricity conversion. This can lead to very high conversion efficiencies, even above 40%.
The technology was first developed for use in space exploration such as the Mars rover missions.
Different techniques use different substrate materials and can be either two-junction or three-junction. Some substrate materials that are used are: Gallium arsenide, Germanium, and Indium phosphide. Because the thin film is deposited (epitaxially) onto a monocrystalline substrate, the applied layers take on the lattice structure of the substrate crystal while maintaining thin film properties.