Metastable defect creation and annealing under illumination in intrinsic hydrogenated amorphous silicon deposited from helium‐silane mixtures

Abstract

We have investigated in detail the creation and annealing kinetics of metastable defects under illumination up to equilibrium in intrinsic device‐quality hydrogenated amorphous silicon films deposited at a high rate using helium dilution of silane. The carrier generation rate G as well as the light‐soaking temperature T have been varied in order to study their respective influences on degradation and recovery rates and on the steady‐state defect density N _ss. The experimental results show that the annealing rate is increased under illumination although our films have a weaker dependence of N _ss on G and T than in films deposited with pure silane. These results are discussed in the light of a simple phenomenological model which has already been successful in describing metastable phenomena in standard samples. Satisfactory fits to the kinetics are obtained as well as quantitative information about the main parameters of our rate equation.