fig3

Figure 3. High-performance flexible MO TFTs employing multiple channel layers. (A) Photograph, schematic diagram, and transfer characteristics of TiO_x/IGZO TFT on PI before and after bending. Reproduced with permission^[82], Copyright 2015, Elsevier; (B) Schematics of MO TFTs employing heterojunction and QSL channel layer, transfer properties of different oxide-based channel layers including ZnO and In₂O₃ and Arrhenius plots of saturation mobility depend on temperature for ZnO, In₂O₃, heterojunction, and OSLs-based TFTs measured at V_G = 80 V and V_D = 100 V. Reproduced with permission^[125], Copyright 2015, Wiley-VCH; (C) Schematics and transfer characteristics of 3C-TFTs and IZI-TFTs. Reproduced with permission^[99], Copyright 2022, Wiley-VCH; (D) Transfer characteristics of D4 Ga₂O₃/ZnO-stack TFTs and flexible Ga₂O₃/ZnO TFT with different folding cycles (up to 100k) and threshold voltage shift of flexible Ga₂O₃/ZnO TFT with a different folding cycle; the insets show schematic diagram for Ga₂O₃ and ZnO films on ZrO_x and the photograph of a foldable device. Reproduced with permission^[98], Copyright 2022, American Chemical Society. MO: Metal oxide; TFTs: thin-film transistors; IGZO: indium gallium zinc oxide; PI: polyimide; QSL: quasi-superlattice; 3C-TFTs: triple-coated indium oxide; IZI-TFTs: indium oxide/zinc oxide/indium oxide.