Electrical, Optical and Mechanical Properties of Thin Films

Containing Purified and Length-sorted Single Wall Carbon Nanotubes .

 

Daneesh Simien, Jeffery Fagan, and Jan Obrzut

 

Polymers Division, MSEL

Bldg 224, Rm A219, MS 8542

301-975-6895

dsimien@nist.gov

 

 

 

Transparent conductive thin films of single walled carbon nanotube (SWNT) networks are becoming increasingly attractive for electronic applications such as flexible transparent electrodes. The optoelectronic performance of these SWNT networks can be continuously improved as its chemical and physical characteristics are optimized to increase conductivity while reducing their layer thickness to approach 2-dimensional structures.  In our work we present the electrical, optical and mechanical properties these near 2-D networks made from unsorted and length sorted SWNTs, in an effort to deduce geometric factors which can link the film structure to its performance characteristics.  The electrical properties were measured using impedance spectroscopy while the optical properties were measured using a UV-VIS-NIR spectrophotometer equipped with a reflectance measurement capability. Mechanical measurements were made using Strain Induced Elastomer Buckling Instability Technique (SIEBIT) developed by Stafford et al1. SWNT films were transferred to the surface of pre-strained polydimethylsiloxane (PDMS) to induce buckling in the SWNT network layer due to applied compressive stresses. The wavelength of these buckling features can be linked to the modulus of the film.

 

1.        Stafford, C. M.; Harrison, C.; Beers, K. L.; Karim, A.; Amis, E. J.; VanLandingham, M. R.; Kim, H. C.; Volksen, W.; Miller, R. D.; Simonyi, E. E. Nat. Mater. 2004, 3, 545-550.