Alta Devices has been trading places with the National Renewable Energy Laboratories (NREL) in holding world record efficiencies for single- and dual-junction solar cells at one sun (not concentrated). Their gallium-arsenide technology includes a layer of indium gallium phosphide (InGaPh), which the firm says utilizes photons more efficiently. According to Alta Devices, “Alta has achieved this breakthrough by modifying its basic ‘single-junction’ gallium arsenide (GaAs) material. The company’s dual junction technology builds on the basic GaAs approach, but implements a second junction (or layer) with Indium Gallium Phosphide (InGaP). Because InGaP uses high-energy photons more efficiently, the new dual-junction cell generates more electricity from the same amount of light than a single-junction device. With this breakthrough, Alta currently holds both the dual-junction and single-junction records at 31.6% and 28.8%, respectively.” Alta claims, that for a typical HALE (high altitude long endurance) UAV aircraft, their solar material requires less than half of the surface area and weighs one-fourth as much while …