Highly Uniform and Stable Transparent Electromagnetic Interference Shielding Film Based on Silver Nanowire–PEDOT:PSS Composite for High Power Microwave Shielding

Abstract Electromagnetic interference (EMI) shielding materials, especially ones with excellent shielding effectiveness (SE), high optical transmittance, long‐term stability as well as high uniformity, are urgently desired to meet the requirements of many applications. Herein, an extremely transparent, stable and uniform silver nanowire (Ag NW)–poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) composite film as an EMI shielding material is prepared, which possess excellent shielding capability to both small signal and high power microwaves (HPM). The composite film exhibits SE of 30.5 dB in the frequency range of 1–12 GHz (small signal) and simultaneously has an optical transmittance of 91.0%. The SE continuously increases to 41.4 dB, while the optical transmittance still maintains at 81.1%. The composite film is very uniform, and its SE is almost unchanged even when exposed in air for a year. The SE of this composite film under the excitation of HPM is also thoroughly investigated. The HPM SE is much larger than that of small signal. As the power density of HPM is increased, the SE firstly remains unchanged, then continuously increases, and finally saturates. The SE exceeds 50 dB with the excitation power density of 40 W. More interestingly, the SE is saturated at a fixed HPM power density.