LIGHT-INDUCED DEFECT CREATION IN A-SI-H - METASTABLE DEFECTS OR METASTABLE H-ATOMS

In hydrogenated amorphous silicon (a-Si:H) the increase of the metasta ble defect density is usually described by an empirical two-parameter stretched exponential (SE) dependence on the illumination time (charac teristic time tau(SE) and dispersion parameter, beta). In this study, an analytic one-parameter function is obtained from a microscopic mode l based on the formation and trapping of light-induced metastable H at oms. A comparison of the empirical SE parameters with the microscopic metastable model shows that these parameters are closely related to th e steady-state H/defect density. (C) 1998 Elsevier Science B.V. All ri ghts reserved.