DO IMPURITIES AFFECT THE OPTOELECTRONIC PROPERTIES OF A-SI-H

The concentrations of H, B, C, N, O, F, Na, Cl, Cr, and Ge in 42 devic e-grade a-Si:H samples were determined by secondary ion mass spectrome try (SIMS). B, Na, Cl, Cr, or Ge were not detected, The concentrations of C, N, and O vary by factors of up to similar to 100, and depend on deposition technique, deposition system, and source gas. The annealed state defect density N-ann and the saturated light-induced defect den sity N-sat are independent of impurity content. The saturated defect d ensity cannot originate in N, and probably not in C. Oxygen affects th e dark conductivity sigma(d) its activation energy E(a), and the ratio of photo to dark conductivity sigma(ph)/sigma(d) in the annealed stat e.