Second controlled light-soaking experiment for amorphous silicon modules

Dual-junction and triple-junction amorphous silicon modules from three manufacturers were subjected to light soaking at 1-sun intensity at 50°C, loaded to the maximum power point, for 1000-2000 hours, with annealing to 70°C in the dark after 1000 hours. Performance characterization was done periodically, both under a pulsed solar simulator and outdoors. Aperture-area efficiencies as high as 9.1% were obtained after 1000 hours of light-soaking. The power output after 1000 hours of light soaking and subsequent partial annealing ranged from 77% to 92% of the initial power output. The recovery in power due to annealing was 4%-6.5%. For a-Si/a-Si-type modules, stabilized performance was reached before 1000 hours. The validity of the results is discussed in detail