Estudio de los procesos hopping a través del modelo difusional en materiales nanocristalinos usados para aplicaciones fotovoltaicas

Here, we present variable range hopping (VRH) models, nearest neighbor hopping (NNH) and potential barriers
present at the grain boundaries, as well as mechanisms of electrical transport predominant in semiconductor
materials for photovoltaic applications. We performed dark conductivity measures according to temperature
for low temperature regions between 120 and 400 K in Si and Cu3BiS2 and Cu2ZnSnSe4 compounds. Using
the percolation theory, we obtained hopping parameters and the density of states near the Fermi, N(EF) level
for all samples. Using the approach by Mott for VRH, we obtained the diffusion model, which established
the relationship between conductivity and density of defect states or localized gap states of the material. The
comparative analysis between models evidenced that it is possible to obtain improvement of an order of
magnitude in the values of each of the hopping parameters that characterize the material.