Highly efficient and stable transparent electromagnetic interference shielding films based on silver nanowires. Issue 27 (2nd July 2020) - Zhu, Xingzhong
Abstract : A stable transparent electromagnetic interference shielding film is realized based on silver nanowires by integrating a polymer layer. Abstract : Transparent electromagnetic interference (EMI) shielding materials with high optical transmittance and outstanding shielding effectiveness (SE) for optoelectronic devices in visual windows are urgently needed. Herein, we demonstrate the preparation of a transparent EMI shielding film based on silver nanowires (Ag NWs) via a facile Mayer-rod coating method. The electrical conductivity and transmittance of Ag NW-based films can be greatly improved through treatment with NaBH4 and the lamination of poly(diallyldimethyl-ammonium chloride). The coverage of the polymer decreases the surface roughness, with no damage on the uniform mesh of the Ag NWs. The Ag NW/PDDA composite films present a sheet resistance of 22 Ω sq −1 at a transmittance of 95.5%, better than that of commercial indium tin oxide (ITO). The excellent optoelectrical performance of the Ag NW/PDDA composite film is further ascertained by fitting the transmittance with the resistance, with a figure of merit of 443. The Ag NW/PDDA composite films in this study exhibit greatly improved stability during 25 °C/65% RH aging for 35 days with the assistance of the coverage layer. Moreover, the EMI SE of the Ag NW/PDDA composite films is 28 dB on average at a transmittance of 91.3%, and continuously increases to 31.3 dB while the optical transmittance is still maintained at 86.8%, which is superior to those of most reported transparent EMI shielding materials. Taken together, the excellent optical transmittance and EMI shielding performance of the Ag NW/PDDA composite film make it an outstanding transparent EMI shielding material in optoelectronic devices, such as aerospace equipment, medical devices, communication facilities, and electronic displays.