Charge deep-level transient spectroscopy (Q-DLTS) has proved to be a powerful tool for investigating the defect-state distribution in hydrogenated amorphous Si (a-Si:H) in both annealed and light-soaked states. Q-DLTS experiments were reported which were designed to further investigate a recently published model for the Staebler–Wronski effect (SWE). By subjecting an a-Si:H based metal/oxide/semiconductor structure to negative (positive) bias voltage during the annealing above the equilibration temperature a programmed p-type (n-type) defect-state distribution could be established in the undoped a-Si:H layer. In this way defect-state engineering in a-Si:H was achieved that permitted the study of the role of different components of the defect-state distribution in the light-induced degradation process. Additional possibility to control the role of a particular defect-state component in the degradation process was to apply a bias voltage also during light soaking. The observed changes in the programmed defect-state distributions due to light soaking under various conditions give additional information on the Staebler-Wronski effect and could be interpreted with the present model for the Staebler-Wronski effect.

Defect-State Engineering in a-Si:H - an Effective Tool for Studying Processes during Light-Induced Degradation. V.Nádaždy, R.Durný, M.Zeman: Journal of Non-Crystalline Solids, 2006, 352[9-20], 1059-63