Fabrication of fractal Ag mesh/FTO transparent electrodes/heaters with enhanced electrical conductivity based on mesh hierarchy and shape optimization

• Published in: Optics and laser technology Vol. 168; p. 109895
• Main Authors: Huang, Li-jing, Zhang, Meng, Wang, Zi-yan, Zhao, Shuai-yu, Ji, Hui, Li, Bao-jia
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2024
• Subjects: Fractal Ag mesh/FTO; Laser etching; Mesh hierarchy; Mesh shape; Transparent electrode (TE); Transparent heater (TH); Fractal Ag mesh/FTO; Mesh shape; Transparent electrode (TE); Transparent heater (TH); Mesh hierarchy; Laser etching
• ISSN: 0030-3992; 1879-2545
• DOI: 10.1016/j.optlastec.2023.109895

[Display omitted] •Introduce fractal-structured meshes into Ag mesh transparent electrodes (Ag MTEs).•Laser direct writing was used to prepare the fractal Ag MTEs on FTO/glass substrates.•Effects of mesh hierarchy and shape on the fractal Ag MTE properties were studied.•TE comprehensive performance especially electrical conductivity was greatly enhanced.•The fractal level-3 hexagon Ag mesh/FTO transparent heater had fast response ability. In the present work, fractal-structured meshes were introduced into the design of Ag mesh transparent electrodes (Ag MTEs), and the as-designed fractal Ag MTEs with different mesh hierarchies and shapes were prepared on FTO/glass substrates via laser etching and polyvinyl pyrrolidone (PVP) coating-assisted peeling off of undesired sputtered Ag layers. The results indicated that the electrical conductivity of the FTO/glass substrates was greatly improved on the premise of small influences on optical transmittance resulted from the presence of Ag mesh wires, thus significantly improving their comprehensive performances. It was found that the fractal level-3 hexagonal Ag mesh/FTO TE had the optimal comprehensive performance, displaying a figure of merit of 4.67 × 10–2 Ω−1 that far surpassed the original FTO/glass substrate. The transparent heater (TH) fabricated from the fractal level-3 hexagonal Ag mesh/FTO TE showed a fast heating performance, which was verified by achieving a high saturated temperature of 130.4 ℃ within ∼85 s under an extremely low input voltage of 2.0 V. Also 25 switching cycles and a deicing test demonstrated its performance stability and application potential. Finally, the fractal level-3 hexagonal Ag mesh TEs/THs were prepared on glass and flexible polyethylene terephthalate (PET) substrates for comparison, highlighting the significance of using the FTO/glass substrate. The fractal-structured meshes based on mesh hierarchy and shape optimization can achieve a significant improvement in comprehensive performance, especially electrical conductivity, which has made a good foundation for future design and research on higher-performance TEs.