A dimensionless joint density of states formalism for the quantitative characterization of the optical response of hydrogenated amorphous silicon

We simplify the empirical model of O'Leary and Malik [J. Appl. Phys. 92, 4276 (2002)] for the density of state functions associated with hydrogenated amorphous silicon, reducing the number of independent modeling parameters from six to five as a result. As a consequence of this simplification, we find that we are able to cast our joint density of states (JDOS) evaluations into a dimensionless formalism, this formalism providing an elementary and effective platform for the determination of the underlying modeling parameters from experiment. We then justify our simplification by showing, for reasonable hydrogenated amorphous silicon modeling parameter selections, that our JDOS results are very similar to those determined using the more general approach of O'Leary and Malik. We also show that this simplified model is as effective as its predecessor in capturing the results of experiment. Finally, we demonstrate the utility of our dimensionless JDOS formalism, using it for the purposes of performing a critical comparative analysis of three different hydrogenated amorphous silicon optical absorption data sets. (C) 2010 American Institute of Physics. [doi:10.1063/1.3385434]