# Tunable terahertz reflection of graphene via ionic liquid gating

## TL;DR

This paper demonstrates a highly efficient, room-temperature, tunable terahertz reflector using graphene and ionic liquid gating, with significant reflectance modulation across a broad spectral range.

## Contribution

It introduces a simple, effective method to modulate graphene's THz reflectance via ionic liquid gating, expanding potential applications in THz optical components.

## Key findings

- Reflectance modulated from 0.79% to 33.4%
- Effective across 0.1 - 1.5 THz range
- Room temperature operation

## Abstract

We report a highly efficient tunable THz reflector in graphene. By applying a small gate voltage (up to 3 V), the reflectance of graphene is modulated from a minimum of 0.79% to a maximum of 33.4% using graphene/ionic liquid structures at room temperature, and the reflection tuning is uniform within a wide spectral range (0.1 - 1.5 THz). Our observation is explained by the Drude model, which describes the THz wave-induced intraband transition in graphene. This tunable reflectance of graphene may contribute to broadband THz mirrors, deformable THz mirrors, variable THz beam splitters and other optical components.

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Source: https://tomesphere.com/paper/1702.00114