TALLINN, Estonia (ESA PR) — This crystal of iron pyrite, just four hundredths of a millimetre in size, could function as the light absorbing layer of a tiny solar cell – potentially a promising future source of power on the Moon.

Working with Estonia’s Tallinn University of Technology (TalTech), ESA has studied the production of sandpaper-like rolls of such microcrystals as the basis of monograin-layer solar cells.