Universal bias dependence of excess current induced by self-heating effect for a-Si:H TFTs

A universal bias correlation of the excess current induced by the self-heating effect is found with the dependence on the dissipated power for a-Si:H thin-film transistors (TFTs). By inspecting the characteristics of I-DS/W versus W, the channel width for TFTs without the self-heating effect is identified. From the difference of the total current and the nonself-heating one, the excess current is extracted. Based on the transport mechanism, together with the intrinsic nature of the direct correlation between lattice temperature and joule heating, the underlying mechanism for the self-heating effect of a-Si:H TFTs is investigated. This discovery will be beneficial to further establish the physics-based model for the self-heating effect of a-Si:H TFTs.