Wei Miaoqing, Zhang Dainan, Li Yuanpeng, Zhang Lei, Jin Lichuan, Wen Tianlong, Bai Feiming, Zhang Huaiwu
State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054, People's Republic of China.
Nanoscale Res Lett. 2019 May 10;14(1):159. doi: 10.1186/s11671-019-2996-9.
In this paper, we demonstrate a trilayer hybrid terahertz (THz) modulator made by combining a p-type silicon (p-Si) substrate, TiO interlayer, and single-layer graphene. The interface between Si and TiO introduced a built-in electric field, which drove the photoelectrons from Si to TiO, 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/TiO/p-Si hybrid nanostructures exhibit great potential for terahertz broadband applications, such as terahertz imaging and communication.
在本文中，我们展示了一种由p型硅（p-Si）衬底、TiO中间层和单层石墨烯组合而成的三层混合太赫兹（THz）调制器。Si和TiO之间的界面引入了一个内建电场，该电场将光电子从Si驱动到TiO，然后电子注入到石墨烯层中，导致石墨烯的费米能级转移到更高的导带。石墨烯的电导率会增加，从而导致太赫兹波透射率降低。由此实现了太赫兹传输调制。我们观察到在0.3至1.7太赫兹的频率范围内太赫兹传输的宽带调制，并且在适当的光激发下具有88%的大调制度。结果表明，石墨烯/TiO/p-Si混合纳米结构在太赫兹宽带应用（如太赫兹成像和通信）方面具有巨大潜力。
