title: Ultrasensitive terahertz modulation by silicon-grown MoS2 nanosheets.
abstract: Two-dimensional (2D) materials play more and more important roles these days, due to their broad applications in many areas. Herein, we propose an optically-pumped terahertz (THz) modulator, based on Si-grown MoS2 nanosheets. The broadband modulation effect has been proved by THz time domain spectroscopy and numerical simulation. The modulation depth of this Si-grown MoS2 nanosheet can reach over 75% under the low pumping power of 0.24 W cm(-2), much deeper than that of bare silicon. By theoretical models and simulation, it is proved that the broadband modulation effect can be described as a free carrier absorption for THz waves in the Drude form. Importantly, by a catalyst mechanism in the Si-grown MoS2, it is concluded that the MoS2-Si heterostructure enables the MoS2 to catalyze more carriers generated on the Si surface. This novel 2D material has a high effective modulation on THz waves under a low pumping power density, which affords it a promising potential in THz applications.
authors: Institute of Modern Optics, Nankai University, Key Laboratory of Optical Information Science and Technology, Ministry of Education, Tianjin 300071, China. fanfei_gdz@126.com.
authors: Sai
authors: S
authors: Chen
authors: Institute of Modern Optics, Nankai University, Key Laboratory of Optical Information Science and Technology, Ministry of Education, Tianjin 300071, China. fanfei_gdz@126.com and Cooperative Innovation Centre of Terahertz Science, Chengdu, Sichuan 610054, China.
authors: Fei
authors: F
authors: Fan
authors: School of Electronics Information Engineering, Tianjin Key Laboratory of Film Electronic and Communication Device, Tianjin University of Technology, Tianjin 300384, China. kikosi@126.com.
authors: Yinping
authors: Y
authors: Miao
authors: North China Research Institute of Electro-optics, Beijing 100015, China.
authors: Xiaotong
authors: X
authors: He
authors: School of Electronics Information Engineering, Tianjin Key Laboratory of Film Electronic and Communication Device, Tianjin University of Technology, Tianjin 300384, China. kikosi@126.com.
authors: Kailiang
authors: K
authors: Zhang
authors: Institute of Modern Optics, Nankai University, Key Laboratory of Optical Information Science and Technology, Ministry of Education, Tianjin 300071, China. fanfei_gdz@126.com and Cooperative Innovation Centre of Terahertz Science, Chengdu, Sichuan 610054, China.
authors: Shengjiang
authors: S
authors: Chang