A Temperature Dependent Drain Current Model For Thin-Film Transistors

Current-voltage(IV)characteristics of Thin-Film Transistors(TFT)are investigated.Based on the Pao-Sah model,an IV model applicable for different operation temperatures and different drain voltages is established.We can get the density of states distribution and other parameters by fitting the model to experiment data.We verified our model on three kinds of TFTs including a-IGZO TFT,poly-Silicon TFT based on metal induced lateral crystallization(MILC)and poly-Silicon TFT based on excimer laser annealing(ELA).It is important for circuit design and analysis to have a reliable drain current model under different drain voltage,different temperature and different kinds of devices.In previous works,temperature dependence of TFT subthreshold current follows the well-known Meyer-Neldel rule(MNR),and the same phenomenon is observed in our experiment data.Thus,we can infer that the Pao-Sah model must be inherently consistent with the MNR.Based on our model,we derive an analytical expression for TFT subthreshold current which is compatible with MNR and physical origin of MNR is given.