On the validity of difiusional model in determination of electric transport parameters of semiconductor compound

In this work we have studied the variable range hopping as a predominant electronic transport mechanism for semiconductor materials used as absorbent layer in photovoltaic devices. Dark conductivity measurements were carried out from 120 to 420 K in Si, Cu₃BiS₃, SnS, Cu ₂ZnSnSe₄, and CuInGaSe2 thin-lms. In the low-temperature range, variational range hopping was established for all samples. Using classical equations from the percolation theory and the difiusional model, the density of states near the Fermi level (NF), as well as the hopping parameters (W activation energy and R hopping range) were calculated. A correlation between both models allowed us to evaluate the validity of the difiusional model in semiconductor compounds.