Staebler-Wronski effect as a function of the Fermi level position and structure of nondoped, amorphous, hydrated silicon

The photoconductivity degradation rates γ (σ _ph∼t ^−γ ) of nondoped, amorphous, hydrated silicon films deposited at T _s =300–400 °C and subjected to illumination for 5 h at 300 K (light source 100 mW/cm², λ<0.9 μm) were investigated. It was shown that the degradation rate γ depends on the preillumination position of the Fermi level ɛ _c −ɛ _F and often is not directly related to the hydrogen content in the film. It was found that there are correlations between the value of γ and the bonds in the silicon-hydrogen subsystem isolated SiH and SiH₂ complexes, clusters (SiH)_n, and chains (SiH₂)_n]. Fiz. Tekh. Poluprovodn. 32, 484–489 (April 1998)