Based on weak bond dangling bond conversion, a complete quantitative solution for the distribution of gap states in a-Si:H in equilibrium and general nonequilibrium conditions can be derived. In this picture the density of states distribution, apart from the structural equilibration between Si-Si-bonds, Si-H-bonds, and Si-dangling bonds and a Gaussian spread of available defect energies, is completely governed by the concentrations of free carriers and the resulting electronic occupation functions in the gap. The model is shown to account for the vast majority of experimental data regarding equilibrium and so called saturated defect densities, such as their dependence on temperature, illumination intensity, band gap, hydrogen content and slope of band tails. Moreover experimental data of photoconductivity, μr-products of electrons and holes versus temperature and light intensity as well as versus position of Fermi level in intrinsic and moderately doped a-Si:H films have been predicted more accurately than by any standard defect model.

Date Published: 9 December 1992
PDF: 12 pages
Proc. SPIE 1729, Optical Materials Technology for Energy Efficiency and Solar Energy Conversion XI: Photovoltaics, Photochemistry, Photoelectrochemistry, (9 December 1992); doi: 10.1117/12.130560

Published in SPIE Proceedings Vol. 1729:
Optical Materials Technology for Energy Efficiency and Solar Energy Conversion XI: Photovoltaics, Photochemistry, Photoelectrochemistry
Anne Hugot-Le Goff; Claes-Goeran Granqvist; Carl M. Lampert, Editor(s)