Abstract-Terahertz and optical study of monolayer graphene processed by plasma oxidation

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 Kim¹

¹Department of Physics and Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749, Republic of Korea
²Department of Mechanical Engineering, Yonsei University, Seoul 120-749, Republic of Korea 

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

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.

© 2013 American Institute of Physics