Thin and flexible transparent conductors with superior bendability having Al-doped ZnO layers with embedded Ag nanoparticles prepared by magnetron sputtering

Abstract

In this work, an attempt has been made to develop thin and flexible transparent conductors based on the interfaces of Ag nanoparticles (AgNP) and Al:ZnO (AZO) deposited by sequential magnetron sputtering. The entire deposition process is completed within 20–28 min without breaking vacuum thereby preventing post-deposition oxidation of Ag NPs. The co-existence of high transmittance and low sheet resistance along with stability under mechanical bending is a bit difficult to achieve in bare AZO thin film having thickness below 200 nm. The resistivity of the optimized AZO/AgNP/AZO composite structure is significantly low at 3.3 × 10−5 Ω cm, which is two orders lower than that of AZO thin film of similar thickness. The figure of merit of the optimized composite structure peaks at 39.0 mΩ−1 corresponding to Ag NPs growth period of 5 min. The novel fabrication of AZO/AgNP interface in a dry and vacuum environment facilitates superior bending stability required for a flexible transparent conductor. The findings suggest that a system of two thin layers of AZO with embedded Ag NPs can be a potential candidate as an indium free transparent conductor for the next generation optoelectronic device.