Total light absorption in graphene

TL;DR

This paper demonstrates that a single patterned sheet of doped graphene can achieve 100% light absorption, with potential applications in tunable infrared detectors and sources.

Contribution

It introduces a method for achieving total light absorption in graphene nanostructure arrays under specific conditions, advancing the design of tunable optoelectronic devices.

Findings

Arrays of doped graphene nanodisks can fully absorb light under critical-coupling conditions.

Full absorption occurs when the particle cross section matches the lattice unit-cell area.

The results are applicable for infrared light detectors and sources with tunable properties.

Abstract

We demonstrate that 100% light absorption can take place in a single patterned sheet of doped graphene. General analysis shows that a planar array of small lossy particles exhibits full absorption under critical-coupling conditions provided the cross section of each individual particle is comparable to the area of the lattice unit-cell. Specifically, arrays of doped graphene nanodisks display full absorption when supported on a substrate under total internal reflection, and also when lying on a dielectric layer coating a metal. Our results are relevant for infrared light detectors and sources, which can be made tunable via electrostatic doping of graphene.