A re-examination of experimental evidence on the spectral dependence of the optical transition matrix element associated with thin-film silicon

We analyze the error associated with the optical transition matrix element spectral dependencies for hydrogenated amorphous silicon and crystalline silicon found by Jackson et al. (Phys Rev B 31:5187–5198, 1985). We find that this error is considerable for photon energies less than 1.5 eV. This suggests that spectral dependencies for the optical transition matrix element, other than those proposed by Jackson et al., are possible for photon energies less than 1.5 eV. With this limitation in mind, we then fit a Lorentzian peak to the crystalline silicon experimental optical transition matrix element result of Jackson et al. Within the framework of the damped harmonic oscillator perspective, plotting the term related to the location of the resonant frequency as a function of the damping coefficient, for a number of thin-film silicon experimental results, we have found a relationship between these model parameters. We suspect that this dependence has important implications for the optical response of various forms of thin-film silicon and related materials.