Surface-Potential-Based Analytic DC I-V Model With Effective Electron Density for a-IGZO TFTs Considering the Parasitic Resistance

A surface-potential-based analytic direct-current I-V model for amorphous indium-gallium-zinc-oxide thin-film transistors is proposed by adopting an effective electron density (n(eff)) model for inclusion of both free carriers and localized charges in the channel. The proposed n(eff) is efficient in reducing the error caused by neglecting the localized electron density n(loc) and allows a closed form of the analytic I-V model. The potential drop across the parasitic resistance R-P in the source and drain regions is also fully considered in the model. Finally, we confirmed good agreement of the proposed model with measured I-DS-V-DS characteristics over a wide range of V-GS and V-DS.