A Physical-Based Analytical Model for the Kink Current of Polycrystalline Silicon TFTs

A physical-based analytical kink current model for polycrystalline -silicon (poly-Si) thin-film transistors (TFTs) has been proposed. Two important mechanisms for the kink current, namely carrier impact ionization and the parasitic bipolar junction transistor effect, are physically included in the model without introducing any artificial parameters. The proposed kink current model is fully compatible with existing ON-state drain current models of poly-Si TFTs. Model parameter extraction procedure is presented, which is based on a group of output characteristics of poly-Si TFTs with different channel lengths. The model prediction straightforwardly calculated with a set of extracted parameters is verified by excellent agreement with experimental output characteristics measured from TFTs over a range of channel lengths and gate voltages.