Disordered photonics behavior from terahertz to ultraviolet of a three-dimensional graphene network

Luca Tomarchio,Antonio Grilli,Suresh Kukunuri,Martina Romani,Mariangela Cestelli Guidi,Samuel Jeong,Salvatore Macis,Yoshikazu Ito,Sen Mou,Kailong Hu,Augusto Marcelli,Annalisa D’Arco,Stefano Lupi

doi:10.1038/s41427-021-00341-9

Abstract

The diffusion of light by random materials is a general phenomenon that appears in many different systems, spanning from colloidal suspension in liquid crystals to disordered metal sponges and paper composed of random fibers. Random scattering is also a key element behind mimicry of several animals, such as white beetles and chameleons. Here, random scattering is related to micro and nanosized spatial structures affecting a broad electromagnetic region. In this work, we have investigated how random scattering modulates the optical properties, from terahertz to ultraviolet light, of a novel functional material, i.e., a three-dimensional graphene (3D Graphene) network based on interconnected high-quality two-dimensional graphene layers. Here, random scattering generates a high-frequency pass-filter behavior. The optical properties of these graphene structures bridge the nanoworld into the macroscopic world, paving the way for their use in novel optoelectronic devices.

Highlights

IntroductionDue to the advances of nanotechnology and the discovery of various 2D functional materials, in recent years there has been a growing interest for extending their extraordinary properties to three-dimensional (3D) ordered and disordered structures.This is true for graphene, since its unique electrical[1,2,3,4,5], thermal[6], and optical properties[7,8,9,10,11,12] can be extended into 3D structures by stacking high-quality monolayer graphene sheets into a wide variety of three-dimensional networks[13,14,15]
A first sample (S1) is undoped, while the second (S2) has been doped with nitrogen and shows a DC conductivity of approximately 70 S/cm, nearly a factor 140 larger than the undoped conductivity (0.5 S/cm). Both samples have a thickness of approximately 1 mm and are composed on average of 12 graphene layers. Their 3D structures were characterized by scanning electron microscopy (SEM) and optical microscopy
Their 3D structures have been characterized by scanning electron microscopy (SEM) and optical microscopy

Summary

Introduction

Due to the advances of nanotechnology and the discovery of various 2D functional materials, in recent years there has been a growing interest for extending their extraordinary properties to three-dimensional (3D) ordered and disordered structures.This is true for graphene, since its unique electrical[1,2,3,4,5], thermal[6], and optical properties[7,8,9,10,11,12] can be extended into 3D structures by stacking high-quality monolayer graphene sheets into a wide variety of three-dimensional networks[13,14,15]. Through the photo/thermoacoustic effect, 3D Graphene sponges provide an efficient transduction of light into sound, covering a very broad acoustic emission range from infrasound (few Hz) to deep ultrasound (few MHz)[61,62,63] Despite those broad applications, very little information is known about the light interaction with 3D graphene structures, where the network composed of pores and branches is expected to interact collectively with a broadband portion of the electromagnetic spectrum[64]

Methods

Results

Conclusion