The Staebler-Wronski Effect and the Thermal Equilibration of Defect and Carrier Concentrations

Abstract

ABSTRACTLight induced degradation of intrinsic Amorphous silicon (a-Si:H) is investigated as a function of temperature. Previous work described an equilibrium framework for the high temperature behavior of dangling bonds defects (DB) 11]; and the temperature dependence of the annealed state photo, σPH, and dark, σD, conductivities of a series of intrinsic a-Si:H Materials deposited over a range of substrate temperatures, 200°C < Ts < 380°C [2]. These results are extended to the light degraded state where elevated temperatures provide for equilibration of the free carrier and DB concentrations. For the equilibrium, light degraded state, both σD and σPH, decrease compared to the annealed state while the ratio, σD/σPH remains unchanged. Relationships between the ratio [DB+]/[DB] and the Fermi level are derived from the equilibrium framework.