Terahertz and optical study of monolayer graphene processed by plasma oxidation

Appl. Phys. Lett. 102, 131901 (2013); http://dx.doi.org/10.1063/1.4795526
(Received 7 February 2013; accepted 26 February 2013; published online 1 April 2013)

Authors: Kyujin Choi¹, Juhwan Lim², J. R. Rani², Hyong Seo Yoon², Juyeong Oh², Taeyoon Hong¹, Taewoo Ha¹, Byung Cheol Park¹, Kyung Ik Sim¹, Seong Chan Jun², and Jae Hoon Kim^1
1 Department of Physics and Institute of Physics and Applied Physics, +Yonsei University, Seoul 120-749, Republic of Korea 
² Department of Mechanical Engineering, +Yonsei University, Seoul 120-749, Republic of Korea 

Abstract

We report on our terahertz and optical study of monolayer graphene grown by chemical vapor deposition and processed by plasma oxidation. The plasma oxidation induces oxygen-related defects, and the resulting disorder increases the sheet resistance of graphene as measured via terahertz spectroscopy. The excitonic absorption peak weakens considerably and blue shifts upon plasma oxidation, resulting in higher transmittance in both the visible and ultraviolet regions. Our oxygen plasma-treated graphene also exhibits a free-carrier doping effect as confirmed by the blue shift of the Raman G band.

... Raman spectroscopy was performed with WITEC ALPHA300M Raman System (excitation at 532 nm, 2.33 eV). The VUV spectrophotometry was carried out with a Cary 5G spectrophotometer and THz-TDS with TeraView TPS Spectra 3000 ... 

More details at: http://apl.aip.org/resource/1/applab/v102/i13/p131901_s1?isAuthorized=no

More about terahertz equipment: http://www.teraview.com/products/index.html