Influence of light-soaking and annealing on the microstructure of a-Si:H deposited at 423 K

Evolution upon light-soaking and annealing of the transport parameters and of the density of states of hydrogenated amorphous silicon prepared under standard conditions (pure silane, low pressure, low power) at 423 K by radio-frequency powered plasma enhanced chemical vapour deposition has been investigated by many techniques. It is shown that both light-soaking and annealing at a higher temperature than the deposition temperature induce structural modifications mainly revealed by an enlargement of the conduction band tail. The structural modifications induced by each process are probably not of the same nature and we conclude that annealing is not always the reverse process of the light degradation.