Highly transparent and conductive Al-doped ZnO/Ag/Al-doped ZnO multilayer source/drain electrodes for transparent oxide thin film transistors

The amorphous IGZO (a-IGZO) transparent TFT with optimized AZO/Ag/AZO S/D electrodes exhibited high transparency (79.17) in the 380-600 nm wavelength region despite the use of a metallic Ag layer due to effective antireflection. In addition, the TTFT with AZO/Ag/AZO S/D electrodes showed higher field effect mobility (_FE: 12.17 cm²/V-s) and on to off current ratio (I_on/off: 9.37 10⁸) than the TTFT with single AZO S/D electrodes due to a reduction in resistivity caused by insertion of the metallic Ag layer. Comparable TTFT performance of the a-IGZO based TTFT to Ti S/D electrodes indicates that the AZO/Ag/AZO multilayer electrode is a promising transparent S/D scheme for high performance TTFTs.