Abstract

In this paper, we demonstrate a trilayer hybrid terahertz (THz) modulator made by combining a p-type silicon (p-Si) substrate, TiO2 interlayer, and single-layer graphene. The interface between Si and TiO2 introduced a built-in electric field, which drove the photoelectrons from Si to TiO2, and then the electrons injected into the graphene layer, causing the Fermi level of graphene to shift into a higher conduction band. The conductivity of graphene would increase, resulting in the decrease of transmitted terahertz wave. And the terahertz transmission modulation was realized. We observed a broadband modulation of the terahertz transmission in the frequency range from 0.3 to 1.7 THz and a large modulation depth of 88% with proper optical excitation. The results show that the graphene/TiO2/p-Si hybrid nanostructures exhibit great potential for terahertz broadband applications, such as terahertz imaging and communication.

Details

Title
High-Performance All-Optical Terahertz Modulator Based on Graphene/TiO2/Si Trilayer Heterojunctions
Author
Wei, Miaoqing 1 ; Zhang, Dainan 1 ; Li, Yuanpeng 1 ; Zhang, Lei 1 ; Jin, Lichuan 1 ; Wen, Tianlong 1 ; Bai, Feiming 1 ; Zhang, Huaiwu 1 

1  State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, People’s Republic of China 
Pages
1-6
Publication year
2019
Publication date
May 2019
Publisher
Springer Nature B.V.
ISSN
19317573
e-ISSN
1556276X
Source type
Scholarly Journal
Language of publication
English
DOI
https://doi.org/10.1186/s11671-019-2996-9
ProQuest document ID
2222871933
Copyright
Nanoscale Research Letters is a copyright of Springer, (2019). All Rights Reserved., © 2019. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.