Analytical current-voltage model for nanocrystalline silicon thin-film transistors

An analytical model for the drain current above threshold voltage, based on an exponential energy distribution of band tail states, has been applied to bottom-gated nanocrystalline silicon (nc-Si) thin-film transistors (TFTs). Analysis of the model shows that the slope of the exponential band tails determines the behavior of the device current-voltage characteristics. Comparison with experimental data shows that few fundamental model parameters, related to the material quality and different physical effects, can be used to describe consistently both output and transfer characteristics of nc-Si TFTs over a wide range of channel lengths.