Highly transparent low resistance Ga doped ZnO/Cu grid double layers prepared at room temperature

Ga doped ZnO （GZO）/Cu grid double layer structures were prepared at room temperature （RT）. We have studied the electrical and optical characteristics of the GZO/Cu grid double layer as a function of the Cu grid spacing distance. The optical transmittance and sheet resistance of the GZO/Cu grid double layer are higher than that of the GZO/Cu film double layer regardless of the Cu grid spacing distance and increase as the Cu grid spacing distance increases. The calculated values for the transmittance and sheet resistance of the GZO/Cu grid double layer well follow the trend of the experimentally observed transmittance and sheet resistance ones. For the GZO/Cu grid double layer with a Cu grid spacing distance of 1 mm, the highest figure of merit （ФTC = 6.19 × 10^-3 Ω^-1） was obtained. In this case, the transmittance, resistivity and filling factor （FF） of the GZO/Cu grid double layer are 83.74%, 1.10 ×10^-4Ω.cm and 0.173, respectively.