The development of technologies for electromagnetic wave contamination has garnered attention. Among the various electromagnetic wave frequencies, for high frequencies such as those in the K and Ka ranges, there is a limitation of using only the properties of a single material. Therefore, it is necessary to improve the absorption coefficients by increasing the path of electromagnetic waves through internal scattering at an interface or a structure inside the material. Here, we accurately demonstrated the role of Sn in the growth of an indium tin oxide (ITO) nano-branch structure and grew high-density ITO nano-branches with the lowest thickness possible. Consequently, we obtained shielding efficiencies of 21.09 dB (K band) and 17.81 dB (Ka band) for a film with a thickness of 0.00364 mm. Owing to the significantly high specific shielding efficiency and low thickness and weight, it is expected to be applied in various fields.
This study was supported by the National Research Foundation (NRF) of Korea grant-funded by the Korean government (MSIT) (RS-2023-00208311, 2021R1A4A1031357 and 2022M3H4A1A04096380).