THE RELATIONSHIP BETWEEN THE DISTRIBUTION OF ELECTRONIC STATES AND THE OPTICAL-ABSORPTION SPECTRUM OF AN AMORPHOUS-SEMICONDUCTOR - AN EMPIRICAL-ANALYSIS

An elementary empirical model for the distribution of electronic state s of an amorphous semiconductor is presented. Using this model, we det ermine the functional form of the optical absorption spectrum, focusin g our analysis on the joint density of states function, which dominate s the absorption spectrum over the range of photon energies we conside r. Applying our optical absorption results, we then determine how the empirical measures commonly used to characterize the absorption edge o f an amorphous semiconductor, such as the Tauc gap and the absorption tail breadth, are related to the parameters that characterize the unde rlying distribution of electronic states. We, thus, provide the experi mentalist with a quantitative means of interpreting the physical signi ficance of their optical absorption data. (C) 1997 American Institute of Physics.