Sensitive photo-thermal response of graphene oxide for mid-infrared detection.
This study characterizes the effects of incident infrared (IR) radiation on the electrical conductivity of graphene oxide (GO) and examines its potential for mid-IR detection. Analysis of the mildly reduced GO (m-GO) transport mechanism near room temperature reveals variable range hopping (VRH) for the conduction of electrons. This VRH behavior causes the m-GO resistance to exhibit a strong temperature dependence, with a large negative temperature coefficient of resistance of approximately -2 to -4% K(-1). In addition to this hopping transport, the presence of various oxygen-related functional groups within GO enhances the absorption of IR radiation significantly. These two GO material properties are synergically coupled and provoke a remarkable photothermal effect within this material; specifically, a large resistance drop is exhibited by m-GO in response to the increase in temperature caused by the IR absorption. The m-GO bolometer effect identified in this study is different from that exhibited in vanadium oxides, which require added gold-black films that function as IR absorbers owing to their limited IR absorption capability.
IBS Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University, Suwon 440-746, Republic of Korea. seonglim@skku.edu.
Jung Jun
JJ
Bae
Jung Hyun
JH
Yoon
Sooyeon
S
Jeong
Byoung Hee
BH
Moon
Joong Tark
JT
Han
Hee Jin
HJ
Jeong
Geon-Woong
GW
Lee
Ha Ryong
HR
Hwang
Young Hee
YH
Lee
Seung Yol
SY
Jeong
Seong Chu
SC
Lim