PMID- 18251484
OWN - NLM
STAT- MEDLINE
DCOM- 20080415
LR  - 20080220
IS  - 1520-5126 (Electronic)
IS  - 0002-7863 (Linking)
VI  - 130
IP  - 8
DP  - 2008 Feb 27
TI  - Assessment of chemically separated carbon nanotubes for nanoelectronics.
PG  - 2686-91
LID - 10.1021/ja7106492 [doi]
AB  - It remains an elusive goal to obtain high performance single-walled 
      carbon-nanotube (SWNT) electronics such as field effect transistors (FETs) 
      composed of single- or few-chirality SWNTs, due to broad distributions in 
      as-grown materials. Much progress has been made by various separation approaches 
      to obtain materials enriched in metal or semiconducting nanotubes or even in 
      single chiralties. However, research in validating SWNT separations by electrical 
      transport measurements and building functional electronic devices has been 
      scarce. Here, we performed length, diameter, and chirality separation of DNA 
      functionalized HiPco SWNTs by chromatography methods, and we characterized the 
      chiralities by photoluminescence excitation spectroscopy, optical absorption 
      spectroscopy, and electrical transport measurements. The use of these combined 
      methods provided deeper insight to the degree of separation than either technique 
      alone. Separation of SWNTs by chirality and diameter occurred at varying degrees 
      that decreased with increasing tube diameter. This calls for new separation 
      methods capable of metallicity or chirality separation of large diameter SWNTs 
      (in the approximately 1.5 nm range) needed for high performance nanoelectronics. 
      With most of the separated fractions enriched in semiconducting SWNTs, nanotubes 
      placed in parallel in short-channel (approximately 200 nm) electrical devices 
      fail to produce FETs with high on/off switching, indicating incomplete 
      elimination of metallic species. In rare cases with a certain separated SWNT 
      fraction, we were able to fabricate FET devices composed of small-diameter, 
      chemically separated SWNTs in parallel, with high on-/off-current (I(on)/I(off)) 
      ratios up to 105 owing to semiconducting SWNTs with only a few (n,m) chiralities 
      in the fraction. This was the first time that chemically separated SWNTs were 
      used for short channel, all-semiconducting SWNT electronics dominant by just a 
      few (n,m)'s. Nevertheless, the results suggest that much improved chemical 
      separation methods are needed to produce nanotube electronics at a large scale.
FAU - Zhang, Li
AU  - Zhang L
AD  - Department of Chemistry and Laboratory for Advanced Materials, Stanford 
      University, Stanford, California 94305, USA.
FAU - Zaric, Sasa
AU  - Zaric S
FAU - Tu, Xiaomin
AU  - Tu X
FAU - Wang, Xinran
AU  - Wang X
FAU - Zhao, Wei
AU  - Zhao W
FAU - Dai, Hongjie
AU  - Dai H
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20080202
PL  - United States
TA  - J Am Chem Soc
JT  - Journal of the American Chemical Society
JID - 7503056
RN  - 0 (Nanotubes, Carbon)
RN  - 9007-49-2 (DNA)
SB  - IM
MH  - DNA/chemistry
MH  - Electronics/*methods
MH  - Luminescent Measurements/methods
MH  - Microscopy, Atomic Force/methods
MH  - Nanotechnology/*methods
MH  - Nanotubes, Carbon/*chemistry
MH  - Particle Size
MH  - Spectrophotometry, Ultraviolet/methods
MH  - Spectroscopy, Near-Infrared/methods
EDAT- 2008/02/07 09:00
MHDA- 2008/04/16 09:00
CRDT- 2008/02/07 09:00
PHST- 2008/02/07 09:00 [pubmed]
PHST- 2008/04/16 09:00 [medline]
PHST- 2008/02/07 09:00 [entrez]
AID - 10.1021/ja7106492 [doi]
PST - ppublish
SO  - J Am Chem Soc. 2008 Feb 27;130(8):2686-91. doi: 10.1021/ja7106492. Epub 2008 Feb 
      2.