Numerical and Experimental Time-Domain Characterization of Terahertz Conducting Polymers

Abstract

A comprehensive framework for the theoretical and experimental investigation of thin conducting films for terahertz applications is presented. The electromagnetic properties of conducting polymers spin-coated on low-loss dielectric substrates are characterized by means of terahertz time-domain spectroscopy and interpreted through the Drude-Smith model. The analysis is complemented by an advanced finite-difference time-domain algorithm, which rigorously deals both with the dispersive nature of the involved materials and the extremely subwavelength thickness of the conducting films. Significant agreement is observed among experimental measurements, numerical simulations, and theoretical results. The proposed approach provides a complete toolbox for the engineering of terahertz optoelectronic devices.

Fabrication and spectroscopic characterization of graphene transparent electrodes on flexible cyclo-olefin substrates for terahertz electro-optic applications

“…Hence, fundamental limitations on the achievable transparency of TCE are much stricter at THz than in the NIR/VIS spectrum. That said, the main solutions for THz-TCE films proposed thus far are graphene [18,67] and transparent conducting polymers, mostly PEDOT:PSS [63,73]. They can be applied on both rigid and flexible substrates without compromising their performance, which makes them suitable for applications such as flexible electronics or sensors [11,74].…”

“…In such cases, extensions of Drude theory have been widely employed, such as generalized Drude functions [61] or the so-called Drude-Smith (DS) model [44]. The latter has been demonstrated as an efficient phenomenological model for the description of thin conducting films [62,63], including the case of graphene [44,60,64].…”

Ultrathin, highly flexible and optically transparent terahertz polarizer based on transparent conducting oxide

“…In the THz region, the dielectric properties of the ITO can be described by Drude model [23,25], which was developed for the description of optical properties of the metal-like materials with high conductivity [31]. The relative dielectric function εr (ω) of ITO can be written as follows:…”