Density of states in hydrogenated amorphous germanium seen via optical absorption spectra

Films thickness effect on structural and optoelectronic properties of hydrogenated amorphous germanium (a-Ge:H)

“…To obtain more information on the disorder parameters E 0V (characterizing the distorted or weak Ge-Ge Bonds) and the deep defect density, N D , the optical absorption spectra α(ℏω) are analyzed using the deconvolution procedure proposed in our previous work [26]. The principle of this method is based to the adjustment of the theoretical model of the density of state (DOS) based on the experimental spectra, after changing some parameters (defect density, disorder parameter and mobility gap).…”

Sub-gap defect density characterization of molybdenum oxide: An annealing study for solar cell applications

“…where  h is the photon energy, C depends on the refractive index and on the momentum matrix elements and is assumed constant for all the optical transitions [42,64,65], Ni(E) and Nf (E) represent the density of the initial occupied states and the final empty states, respectively, and F(E) is the Fermi-Dirac function, which describes the probability of energy bands occupancy.…”

Density of States in Intrinsic and n/p-Doped Hydrogenated Amorphous and Microcrystalline Silicon

“…The principle of this method consists of using a model of DOS suitable to the tetracoordinated amorphous semiconductors [16], to calculate numerically the coefficient of absorption, while modifying systematically the parameters of adjustments of the model to obtain a better reproduction of the experimental spectra on all the range of energy. For more information on this method one can be consult the reference [17]. For the analysis of the absorption spectra, withdrawn from CPM measurement, we used the method of deconvolution and we have developed the necessary programs for the numeral calculation to get information on the defects density of states in the gap and at their distribution in energy.…”