Optical Study of Few‐Layer Graphene Treated by Oxygen Plasma

Abstract

Oxygen plasma treatment is often used to clean the surface or etch graphene for functional structures. Some unique properties such as photoluminescence (PL), energy bandgap engineering, and so on are presented in single‐layer graphene (SLG). Compared with SLG, few‐layer graphene (FLG) has higher luminescence intensity, slower decay rate, and better controllability. It is more universal in the application of new optoelectronic devices and transparent electrodes. So, a systematic study is provided to analyze the mechanism between chemical vapor deposition of few‐layer graphene and oxygen plasma process based on the optical characterization method. Surface morphology, structural defects, resistance change, chemical state, and PL are traced and investigated under different oxygen plasma treatment times. The CO and CO bonds on the surface of the FLG appear to increase and then decrease with oxygen plasma etching based on X‐ray photoelectron spectroscopy (XPS) characterization. A linear square resistance change is presented from 1.4 to 4.8 kΩ sq−1. Besides that, an obvious redshift–blueshift change is produced in fluorescence characteristic spectra. Herein, comprehensive research on the influencing mechanism of graphene and oxygen treatment is exhibited, which provides the potential to construct optoelectronic devices.

Photochemically Patterning Graphene in a Highly Efficient, Anisotropic, and Clean Way

“…The spectrum only has a slight rise from 285.9 to 290.7 cm –1 due to surface oxidation and an extremely low content of oxygen compared with the sp 2 carbon atoms within the detection depth of ∼10 nm. The traits differ from the C 1s broadening of few-layer graphene treated by oxygen plasma. , The discrepancy reveals that the photochemical oxidation proceeds mainly at the surface and that the underlying carbon layers maintain their initial crystalline structure thanks to the nonbombing character of the directional radicals.…”

“…The traits differ from the C 1s broadening of few-layer graphene treated by oxygen plasma. 16,46 The discrepancy reveals that the photochemical oxidation proceeds mainly at the surface and that the underlying carbon layers maintain their initial crystalline structure thanks to the nonbombing character of the directional radicals.…”

“…Graphene, a honey-combed sp 2 carbon structure, has gained some milestone breakthroughs, including high-quality single crystalline graphene growth, − vital fundamental discoveries, , and their applications. , Simultaneously, the discovery of graphene and its fast development have propelled the booming of other two-dimensional (2D) materials. − For the purpose of their chemical modification and patterning, the conventional reactive ion etching (RIE) or its derivative inductively coupled plasma (ICP) RIE has been directly applied to them. , The plasma-based RIE technique is renowned for its high etching efficiency and good anisotropy . However, the highly dynamic charged ions inevitably result in surface amorphization, and the coexisting arbitrary neutral radicals can reduce the etching anisotropy. − For the atom-thick 2D materials, the plasma treatment can drastically degrade the intrinsic properties, like quenching the quantum emission of modified hexagonal boron nitride (hBN) . In order to reduce the ion bombing damage, neutral radical beams are filtered from the plasma to etch graphene mildly. , Moreover, when the RIE technique is combined with the conventional lithography, it is a big challenge to eliminate the surface organic residues from soft masks …”

Synergetic Effect of Plasma‐Treated Graphene Oxide/Polymer Blends for Electrostatic Dissipative Applications

“…[20] Although GO exhibited excellent properties, some functionalization is required to enhance the performance like oxidation, reduction, plasma functionalization. [21,22] Lami et al reported a theoretical review on oxidation, exfoliation, and reduction of GO. Electrical, mechanical, and thermal performance of GO is enhanced due to functionalization.…”