Real-time transmission Mueller polarimetry on hydrogenated polymorphous silicon under current injection

Abstract

We report on the use of an innovative optical characterization technique—real-time Mueller polarimetric imaging in transmission—for the characterization of thin-film silicon solar cells. In this work, we used this technique to monitor the evolution of optical retardance induced by the mechanical stresses in hydrogenated amorphous and polymorphous silicon (a-Si : H and pm-Si : H) p–i–n (PIN) solar cells. Under current injection of 200 mA cm−2, the retardance of the pm-Si : H PIN solar cells decreased, while that of the a-Si : H PIN solar cells showed no significant change. After the current injection, the pm-Si : H PIN solar cells showed dramatic macroscopic changes on a scale of tens of micrometres, such as local peel-off and delamination from the substrate. Our results demonstrate that current injection introduces local stress relaxation, which can be efficiently monitored prior to irreversible damage from a decrease in the retardance of the pm-Si : H PIN solar cells.