Efficient Absorption of Terahertz Radiation in Graphene Polymer Composites

TL;DR

This paper demonstrates that lightweight epoxy-based graphene polymer composites with low graphene content effectively absorb and block terahertz radiation, offering practical electromagnetic shielding solutions.

Contribution

It introduces a new efficient method for THz radiation absorption using low-loading graphene composites in epoxy, suitable for thin-film applications.

Findings

Total shielding effectiveness of 85 dB at 1.6 THz

Effective absorption with less than 1.2 wt. % graphene

Shielding effectiveness increases with frequency

Abstract

We demonstrate that polymer composites with a low loading of graphene, below 1.2 wt. %, are efficient as electromagnetic absorbers in the THz frequency range. The epoxy-based graphene composites were tested at frequencies from 0.25 THz to 4 THz, revealing total shielding effectiveness of 85 dB (1 mm thickness) with graphene loading of 1.2 wt. % at the frequency f=1.6 THz. The THz radiation is mostly blocked by absorption rather than reflection. The efficiency of the THz radiation shielding by the lightweight, electrically insulating composites, increases with increasing frequency. Our results suggest that even the thin-film or spray coatings of graphene composites with thickness in the few-hundred-micrometer range can be sufficient for blocking THz radiation in many practical applications.