Accelerated Stability Testing of Amorphous Modules

Abstract

An effective process optimisation of end of life efficiencies imperatively requires accelerated degradation methods, reducing the delay of stability results from typically 1000 h to 1–2 hours. We have used forward bias current injection at intensities between 100–400 mA/cm² to reach saturation levels within 0.5 hours. The saturation time varies inversely proportional to the square of the generation rate and the final defect density is lower at high temperature, i.e. high annealing rates. The accelerated aging, however, creates more unstable defects with lower activation energies than those generated by conventional AM 1.5 light soaking, which slowly anneal even at room temperature. However, the energy levels of such defects are comparable to light generated defects.