Microlink Devices will work on the commercialization of the inverted metamorphic multi-junction (IMM) solar cell design developed by the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL).
IMM cells can achieve high efficiencies through the integration of three or more semiconductor layers, which are deposited on to a removable gallium arsenide (GaAs) substrate. The design uses a metamorphic buffer layer to grow materials with ideal bandgap for energy production, such as indium gallium arsenide, which are not matched to the substrate.
Using these cells, Microlink has already achieved efficiencies in excess of 32%.
The IMM cell design will be used in combination with Microlink’s epitaxial lift-off (ELO) technology. In this process, active cell solar material is peeled off of a GaAs substrate. Removing this substrate allows for exceptionally light weight solar cells with specific powers of more than 3000 W/kg, says Microlink.
Although the GaAs substrate can be reused after removal in order to reduce costs, given the costly material’s involved in the process it is unlikely that these cells will be seen outside of niche applications such as satellites and drones.
MicroLink’s ELO technology was funded by various U.S. agencies including NASA, DARPA, the Air Force Research Laboratory, the Office of Naval Research, NAVAIR, Army Research Office, Army REF, CERDEC, and the Department of Energy.
The company currently has a contract with Airbus defence and space to provide its technology to the Zephyr S HALE, a fully solar powered, high altitude, unmanned air vehicle, able to carry out similar functions to a satellite.