A simplified joint density of states analysis of hydrogenated amorphous silicon

We propose a simplified empirical model for the density of state functions of hydrogenated amorphous silicon that neglects the conduction band tail electronic states. The corresponding joint density of states function is then computed. We find, while this analysis is considerably simplified, that the resultant joint density of states function compares favorably with that determined from an empirical model for the density of states functions with the conduction band tail taken into account. Analytical and asymptotic results, relating the parameters characterizing the underlying density of states functions with the joint density of states function, are developed. The density of states parameters corresponding to hydrogenated amorphous silicon are then determined through an analysis of some hydrogenated amorphous silicon joint density of states experimental data. It is suggested that this simplified empirical model for the density of states functions will prove of greater utility to the experimentalist. (C) 2002 American Institute of Physics.