Terahertz and infrared spectroscopy of gated large-area graphene.
We have fabricated a centimeter-size single-layer graphene device with a gate electrode, which can modulate the transmission of terahertz and infrared waves. Using time-domain terahertz spectroscopy and Fourier-transform infrared spectroscopy in a wide frequency range (10-10 000 cm(-1)), we measured the dynamic conductivity change induced by electrical gating and thermal annealing. Both methods were able to effectively tune the Fermi energy, E(F), which in turn modified the Drude-like intraband absorption in the terahertz as well as the "2E(F) onset" for interband absorption in the mid-infrared. These results not only provide fundamental insight into the electromagnetic response of Dirac fermions in graphene but also demonstrate the key functionalities of large-area graphene devices that are desired for components in terahertz and infrared optoelectronics.
Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, United States.
Lei
L
Ren
Qi
Q
Zhang
Jun
J
Yao
Zhengzong
Z
Sun
Ryosuke
R
Kaneko
Zheng
Z
Yan
Sébastien
S
Nanot
Zhong
Z
Jin
Iwao
I
Kawayama
Masayoshi
M
Tonouchi
James M
JM
Tour
Junichiro
J
Kono