Annealing Behaviour and Nature of Defects of Light-soaked Microcrystalline Silicon Solar Cells

In this paper, we show that the kinetics of annealing of light-induced defects in microcrystalline silicon is similar to that of amorphous silicon. Dilution series of pin and nip single-junction microcrystalline silicon (μc-Si:H) solar cells were light-soaked (AM 1.5, 1000h at 50°C). Their relative efficiency loss between initial and degraded states depends on the i-layer crystallinity. Subsequent annealing steps at 373°K and 403°K exhibit a continuous decrease of the defectrelated absorption as a function of time. This annealing kinetics follows a stretched exponential behavior, characterized by a relaxation time and a dispersive parameter. The defect relaxation time is thermally activated, with a characteristic energy that is independent of the intrinsic layer crystallinity, and that is lower than the value observed for thermal recovery of degraded a-Si:H.