Interface Hydrogen and Passivation of Amorphous Silicon / Crystalline Silicon Heterojunction

The Si surface passivation by amorphous Si (a-Si:H) layers is investigated, where the a-Si:H layers are grown with different plasma current and methods. A significant improvement in passivation quality (iV
oc
= 738 mV, ≈ 40 mV increase from baseline) is achieved when the a-Si:H growth plasma was interrupted (OFF/ON) at the midway of deposition followed by a post deposition annealing. This improvement is attributed to the homogeneous uniform nucleation and growth of a-Si:H stack layer and layer densification (removal of some hydrogen) during annealing.