Numerical simulation and optimization of metallic network for highly efficient transparent conductive films

Abstract

Metallic networks have been regarded as one of the promising indium tin oxide replacements due to its optoelectronic advantages and possible low-cost manufacturing cost. The electrothermal and optical properties of transparent conductive films (TCFs) are closely related to the geometry of the metallic networks. Therefore, the in-depth understanding of the geometry effect is quite important for designing a desirable metallic network TCF. In this paper, we conducted an in-depth theoretical study on the geometry effect on the electrothermal and optical properties of the metallic network TCF by using a coupled electrothermal model. We found that the metallic wire segments in different directions have different current densities and power densities, which mainly depends on the directions of the electric field. Besides, the inner corner of the branch junctions of networks has a current density 14.5 times higher than the average. The maximum temperature difference inside the network is up to 19.6 K. Importantly, the mechanisms for network breakdown under excessive operating power are summarized as thermal assisted electronic migration and excessive temperature. Finally, we proposed several optimized network geometries with a reduced sheet resistance (48.4%) and internal temperature difference (60.1%). We believed that the outcomes and analyses of this work help us to design the transparent metallic networks with optimal performance and potentially applicable to the transparent heaters and smart windows.