Characterization of Silver Nanowire Layers in the Terahertz Frequency Range

THz Shielding Properties of Optically Transparent PEDOT:PSS/AgNW Composite Films and Their Sandwich Structures

The modern pace of scientific and technological development dictates unprecedented requirements for the speed of information transfer. The THz range is considered one of the most promising and has been actively developing in recent years. Along with the need to develop transmitting devices, the demand for shielding materials in this range, including transparent ones, is also growing. In this work, we present two types of composite films based on silver nanowires and PEDOT:PSS. We characterized these composite films in terms of optoelectrical parameters, as well as shielding characteristics in the THz range. We found that our composite films have a sheet resistance (R□) of about 8.6 ± 1.2 Ω/□ with a transparency of about 83.41% and shielding efficiency is 25.85 dB in the THz region, which makes them excellent candidates for transparent shielding materials. We also made a bilayer sandwich structure from these composite films, which showed a shielding efficiency of about 49.34 dB in the range of 0.2-0.8 THz with a transparency of 66.33%. In addition, we assessed the possibility of real application of the structures in terms of stability to external conditions. Our composite films sustain atmospheric corrosion and maintain stable sheet resistance for 30 days.

Investigation on the Correlation between Dispersion Characteristics at Terahertz Range and Dielectric Permittivity at Low Frequency of Epoxy Resin Nanocomposites

Despite the extensive research on nanocomposites, a fundamental theory on the interface region is still difficult to achieve. In the present paper, we chose epoxy resin and nano-SiO2, nano-SiC, nano-ZnO to prepare three kinds of nanocomposites. The dispersion characteristics at the terahertz range and dielectric permittivity at 1 Hz of epoxy resin-based nanocomposites were investigated. The reduction of the permittivity of nanocomposites at a slight filler concentration was absent at the terahertz range. The measurement results at 1 Hz show that the interaction between nano-SiO2, nano-SiC particles and epoxy resin was strong with the modification of the silane coupling agent. However, the modification of nano-ZnO particles was invalid. The Lorentz harmonic oscillator model was employed to fit the dispersion characteristics. The relevance between the damping constant and the dielectric permittivity at low frequency was established, indicating that the increase in the damping coefficient results from the restriction of the molecular chain motion by the interfacial region. The present results in this paper reveal a bright prospect of terahertz time-domain spectroscopy in establishing the theory of nanocomposite dielectric.