Original concept of cracked template with controlled peeling of the cells perimeter for high performance transparent EMI shielding films

https://doi.org/10.1016/j.surfin.2023.102793

The problem of sputtering of thick metal films on micro and nanotemplates is important for obtaining mesh transparent conductors with excellent optoelectric characteristics. In this work, we demonstrate for the first time the possibility of controlling the degree of peeling of the cell perimeter from the substrate for a cracked template based on egg white by alternating the operations of moistening the template with saturated water vapor and shock drying with hot air. Local peeling of the cracked template cells perimeter makes it possible to increase the thickness of the metal sputtered on the cracked template by more than 1 µm, which is not achievable for other lithographic approaches. Our technique was used to obtain thick Ag meshes with a low sheet resistance of no more than 1.59 Ω/sq and a transparency of about 89.1%. The thick Ag meshes show a shielding efficiency (SE) of 49 dB or 99.998% of the incident power of an electromagnetic wave at a frequency of 1 GHz. In a sandwich geometry, thick Ag meshes, which simulates a real shielding window, the shielding efficiency (SE) reaches 71 dB with a transparency of more than 80%.