Fused silver nanowires with silica sol nanoparticles for smooth, flexible, electrically conductive and highly stable transparent electrodes

Propylene Glycol and Glycerol Addition in Forming Silver Nanowires (AgNWs) for Flexible and Conductive Electrode

Silver nanowires (AgNWs) are promising materials due to their flexibility, high transmittance, high conductivity, and low sheet resistances to replace ITO (Indium Thin Oxide) based electrodes. In this work, we studied the Propylene Glycol and Glycerol addition in Ethylene Glycol solvent to form AgNWs with polyol method. AgNWs was made thin film by spin coating method (with 1 – 3 layers variation) in PET substrate at 3000 rpm. The best morphology AgNWs formed by EG: PG: Gliserol (7 : 0 : 3) solvent composition with average diameter, length, and thickness are 210.32 nm, 6.68 μm, and 2.1 μm respectively. In optical properties, transmittance of AgNWs thin film was in range of 54.6 – 70.6 %. The sheet resistance of 3 layers AgNWs thin film was 2.8 – 30.2 Ω/sq. Sheet resistance of AgNWs thin film was better than ITO-PET (transmittance 60% sheet resistance 45 Ω/sq).

PET/Ag NW/PMMA transparent electromagnetic interference shielding films with high stability and flexibility

Flexible transparent electromagnetic interference (EMI) shielding materials in visual windows are essential for the innovation of optoelectronic devices. Herein, we demonstrate the fabrication of flexible EMI shielding films based on silver nanowires (Ag NWs) and polymethyl methacrylate (PMMA). The purified Ag NWs are uniform in size and morphology, with aspect ratio over 1000. The PET/Ag NW/PMMA flexible transparent conductive films (FTCFs) with a sandwich structure were obtained via Mayer-rod coating of the Ag NWs and spin-coating of the PMMA polymer on a polyethylene terephthalate (PET) substrate. The root mean square roughness value of PET/Ag NW/PMMA FTCFs could decrease from 21 nm to 4 nm due to the filling of PMMA in the interface among Ag NWs. The PET/Ag NW/PMMA FTCFs can achieve a sheet resistance of 21 Ω sq-1 at a transmittance of 95.6%, resulting in a high figure of merit of 447. Moreover, the composite films exhibit remarkable flexibility after 10 000 continuous bending cycles, as well as great stability in harsh environments of 80 °C/80% RH aging for 600 h. An EMI shielding effectiveness (SE) of 21.3 dB in combination with a high optical transmittance of 95.6% for the PET/Ag NW/PMMA FTCFs is sufficient to satisfy the requirement of commercial transparent EMI shielding applications. The absorption component of the SE was demonstrated to play a dominant role in the EMI shielding mechanism. The comprehensive performance (flexibility, stability, transparency and EMI shielding performance) makes the PET/Ag NW/PMMA FTCFs have great potential as a flexible transparent EMI shielding material in emerging flexible optoelectronic devices.

Highly efficient and stable transparent electromagnetic interference shielding films based on silver nanowires

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.

Facile preparation of high conductive silver electrodes by dip-coating followed by quick sintering

With polyol-synthesized silver nanoparticles (AgNPs) as raw materials, the silver electrodes with high conductivity were fabricated via a dip-coating method followed by sintering process, and the effects of the dip-coating and sintering process on the conductivity and surface roughness of silver electrodes were investigated in detail. The silver film with a thickness of 1.97 µm and a roughness of about 2 nm can be prepared after dip-coating at a pulling rate of 500 µm s-1 for 40 coating times. The non-conductive dip-coated silver films are transformed into conductive silver electrodes after conventional sintering in a muffle oven, infrared sintering and microwave sintering, respectively. Compared with high sintering temperature and long sintering time of conventional sintering and infrared sintering, microwave sintering can achieve quick sintering of silver films to fabricate high conductive silver electrodes. The silver electrodes with a sheet resistance of 0.75 Ω sq-1 and a surface roughness of less than 1 nm can be obtained after microwave sintering at 500 W for 50 s. The adjustable dip-coating method followed by quick microware sintering is an appropriate approach to prepare high conductive AgNPs-based electrodes for organic light-emitting diodes or other devices.