NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.

Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.

U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

PUBLICATIONS

Broadband Optical Properties of Graphene by Spectroscopic Ellipsometry

Published

Author(s)

Wei Li, Nhan Van Nguyen, Guangjun Cheng, Angela R. Hight Walker, David J. Gundlach, Yiran Liang, boyuan Tian, Xuelei Liang, Lian-Mao Peng

Abstract

The broadband (0.7 eV to 9.0 eV) optical properties of chemical-vapor-deposition (CVD) grown graphene are determined by spectroscopic ellipsometry. The optical absorption follows the fine structure constant in the energy range from 1.0 eV to 2.0 eV, but deviates to lower below 1 eV. A strong absorption peak is observed at 4.6 eV which is dominated by resonant excitons near the van Hove singularity at M point of the Brillouin zone. A higher energy peak at 6.4 eV is regarded as a result from the excitonic effect of σ-to-σ* transition at Γ point of the Brillouin zone. The dielectric function of multi-layered CVD graphene fabricated by layer transfer was also investigated. We found that the multi-layered graphene resembles the characteristics of CVD single-layer graphene and exfoliated multilayer graphene, leading to a prospect of new potential device applications.
Citation
Applied Physics Letters
Volume
99
Pub Type
Journals

Keywords

grapheme, optical properties, ellipsometry, 2-D materials
Polymers, Optical / photometry / laser metrology, Nanomaterials, Metrology, Materials and Electronics

Citation

Li, W. , Nguyen, N. , Cheng, G. , Hight Walker, A. , Gundlach, D. , Liang, Y. , Tian, B. , Liang, X. and Peng, L. (2015), Broadband Optical Properties of Graphene by Spectroscopic Ellipsometry, Applied Physics Letters (Accessed October 8, 2025)

Issues

If you have any questions about this publication or are having problems accessing it, please contact [email protected].

Created December 10, 2015, Updated October 12, 2021
Was this page helpful?