The Effects of Accelerated Aging Tests on Metamorphic III-V Concentrator Solar Cells Mounted on Substrates

Various stress tests have been applied to metamorphic III-V concentrator solar cells mounted on substrates. The duration of the tests wasup to 3000 hoursin order to provoke accelerated aging and to identify whether any degradation occurs.Effects introduced due to the applied stress were expected to be seen in light IV curve measurements. Therefore, we investigatedthe stressed samplesby light IV measurements under high intensity levels, optical inspection by a light microscope and an elemental analysis by SEM-EDX. Reference samples were used to evaluate the characterization methods for IV measurementsand to confirm the test results. Neither total failuresnor critical degradation in the IV characteristics were observed for more than 70 test samples, which underwentstress procedures including damp heat, thermal cycling, humidity freeze and high temperature tests. Keywords: Multi-junction Solar Cells, Accelerated Aging, Qualification and Testing, Characterization