A device model for amorphous In-Ga-Zn-O thin-film transistors (a-IGZO TFTs) that explains temperature dependence is proposed. It incorporates a carrier-density dependent mobility and a density of subgap traps of a-IGZO. The model parameters were extracted from only one transfer curve of an a-IGZO TFT at a low drain voltage through a simple analytical model. Device simulation based on this model reproduced current-and mobility-gate voltage characteristics of the a-IGZO TFT well over a wide range of bias voltage and temperature (253-393 K). (C) 2013 Elsevier B.V. All rights reserved.