Nano Archive

Monitoring dopants by Raman scattering in an electrochemically top-gated graphene transistor

Das, Anindya and Pisana, S and Chakraborty, B and Piscanec, S and Saha, S. K. and Waghmare, U. V. and Novoselov, K. S. and Krishnamurthy, H. R. and Geim, A. K. and Ferrari, A. C. and Sood, A. K. (2008) Monitoring dopants by Raman scattering in an electrochemically top-gated graphene transistor. NATURE NANOTECHNOLOGY, 3 (4). pp. 210-215.

Full text is not hosted in this archive but may be available via the Official URL, or by requesting a copy from the corresponding author.

Official URL:


The recent discovery of graphene(1-3) has led to many advances in two-dimensional physics and devices(4,5). The graphene devices fabricated so far have relied on SiO2 back gating(1-3). Electrochemical top gating is widely used for polymer transistors(6,7), and has also been successfully applied to carbon nanotubes(8,9). Here we demonstrate a top-gated graphene transistor that is able to reach doping levels of up to 5x10(13) cm(-2), which is much higher than those previously reported. Such high doping levels are possible because the nanometre-thick Debye layer(8,10) in the solid polymer electrolyte gate provides a much higher gate capacitance than the commonly used SiO2 back gate, which is usually about 300 nm thick(11). In situ Raman measurements monitor the doping. The G peak stiffens and sharpens for both electron and hole doping, but the 2D peak shows a different response to holes and electrons. The ratio of the intensities of the G and 2D peaks shows a strong dependence on doping, making it a sensitive parameter to monitor the doping.

Item Type:Article
Subjects:Material Science > Nanofabrication processes and tools
Physical Science > Nanoelectronics
Material Science > Nanostructured materials
Analytical Science > Beam methods
ID Code:468
Deposited On:04 Dec 2008 16:17
Last Modified:19 Feb 2009 16:49

Repository Staff Only: item control page