Improvement in the Figure of Merit of ITO-Metal-ITO Sandwiched Films on Poly Substrate by High-Power Impulse Magnetron Sputtering

High-power impulse magnetron sputtering (HiPIMS) was used to deposit ITO/Ag/ITO (IAgI) and ITO/Cu/ITO (ICuI) sandwiched films on polyethylene naphthalate substrate at room temperature as flexible transparent conductive materials. The hybrid layers were constructed with 40 nm ITO bottom and top layers, and a 5-20 nm Ag or Cu interlayer. The microstructure and optoelectrical properties were estimated for these films with various thicknesses of the metal interlayer. Thanks to the high-power density and highly ionized plasma in the HiPIMS process, the IAgI and ICuI sandwich structures exhibited good crystallinity and smooth surfaces with high optical transmittance and low sheet resistance. The optimal figure of merit was obtained as 101.16 x 10(-3)center dot omega(-1) for the IAgI film and 4.83 x 10(-3)center dot omega(-1) for the ICuI film with the metal interlayer thickness of 10 nm, both of which are higher than that from a similar structure reported via sputtering at room temperature. These results indicate that HiPIMS is a promising technique to deposit transparent conductive films onto soft substrates for applications in flexible optoelectronic devices.

Automated summary

High-power impulse magnetron sputtering (HiPIMS) was used to deposit ITO/Ag/ITO (IAgI) and ITO/Cu/ITO (ICuI) sandwiched films with good crystallinity and smooth surfaces on flexible substrates at room temperature, showing high optical transmittance and low sheet resistance. The films achieved high figure of merit values, indicating the potential of HiPIMS in depositing transparent conductive films for flexible optoelectronic devices.