Effect of Au interlayer thickness on the structural, electrical, and optical properties of GZO/Au/GZO multilayers

• Aggregated Au islands form a continuous film with increasing Au interlayer thickness.
• Resistivity and optical transmittance reduce as the Au interlayer thickness increase.
• GZO/9 nm Au/GZO multilayer exhibited a low resistivity and high peak transmittance.
• The highest figure of merit was obtained at an Au interlayer thickness of 9 nm.

We report on the structural, electrical, and optical properties of Ga-doped ZnO/Au/Ga-doped ZnO (GZO/Au/GZO) multilayers as a function of Au interlayer thickness. Aggregated Au islands formed a continuous film as the thickness of the Au interlayer increased from 3 to 12 nm. Consequently, the sheet resistance, resistivity, and optical transmittance decreased with increasing Au interlayer thickness compared to a GZO single layer. However, a relatively high peak transmittance and a high figure of merit were obtained for an Au interlayer thickness of 9 nm. These results showed that the characteristics of GZO/Au/GZO multilayers could be improved by inserting an Au interlayer of optimized thickness. In addition, it indicated that the GZO/Au/GZO multilayer is the most promising candidates for indium free transparent conducting oxides (TCOs).