Illinois’ Microlink Devices has announced a new efficiency record of 37.75% for cells based on its triple-junction epitaxial lift off (ELO) technology.
The cell was tested under industry standard irradiation conditions (AM1.5g) using a solar simulator, and the efficiency record has been confirmed by the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL). Microlink also states that the cell achieved a power density of more than 3,000 W/kg, a world record for any cell technology.
Microlink’s ELO production process involves the peeling off of thin active cell layers from a gallium arsenide substrate, and is combined with multi junction technology, integrating three or more semiconductor layers, developed by NREL, to achieve the very high efficiencies demonstrated.
Microlink has signed an exclusive deal with NREL for the commercialization of the technology. While the company points out that the substrates made from costly gallium arsenide can be reused to keep costs down, it is unlikely the cells will be cheap enough for application outside of UAVs, satellite and other areas requiring very lightweight solar cells.
“We are continuing to push the limits of what can be achieved with the ELO technology,” says Noren Pan, founder and president of Microlink Devices. “Our triple-junction IMM ELO solar cells combine the highest efficiency with the lowest mass density of any solar cell technology available today.”
The company has also provided its technology to Airbus Defence and Space, and it is used to power the Zephyr HALE, a solar powered unmanned air vehicle which has set several records for uninterrupted flight without refueling.