Electrical conductivity and photoresponse measurements have been carried out on a single-stranded DNA (ssDNA)/single-walled carbon nanotube (SWNT) composite film in comparison to those of a SWNT film. While the temperature-dependent electrical conductivity of the pristine SWNT film was described well by the combined mechanism of a three-dimensional variable-range hopping and hopping conduction, that of the ssDNA/SWNT composite film followed a fluctuation-induced tunneling model. Besides, competition of photoexcited charge carrier generation and oxygen adsorption/photodesorption in the photoresponses of the films was observed and discussed in view of the role of the DNA wrapping. Thus, the biopolymer coating of the SWNTs is shown to play a significant role in modifying the charge dynamics of the composite system.
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea (Project No. 20100029418, No. 2012034779, and Cyclotron Users Program 2012029495). The measurements at the Korean Basic Science Institute (KBSI) are gratefully acknowledged.
ASJC Scopus subject areas
- General Physics and Astronomy