Space qualification of amorphous silicon alloy lightweight modules

We report space qualification testing of lightweight amorphous silicon (a-Si) alloy triple-junction cells and modules in the laboratory and also on board the MIR space station. Triple-junction a-Si alloy solar cells were made on stainless steel using the roll-to-roll manufacturing equipment of United Solar. Electron bombardment at energies of 1 and 3 MeV up to 2.10¹⁴ cm^-2 and proton bombardment of 20 MeV energy up to 1.10¹² cm^-2 cause less than 5% change in the cell power output. No change in the power output was observed after 420 thermal cycles between -170°C and +65°C. Modules made of several interconnected cells (35.56 cm by 3.98 cm) have been undergoing tests on board the MIR space station since November 11, 1998. Telemetry data indicate the power output to be constant within 5%, confirming the laboratory test data