Raman microscopy mapping for the purity assessment of chirality enriched carbon nanotube networks in thin-film transistors
Raman spectroscopy, carbon nanotubes, thin film transistors, microscopy mapping, purity assessment
With recent improvements in carbon nanotube separation methods, the accurate determination of residual metallic carbon nanotubes in a purified nanotube sample is important, particularly for those interested in using semiconducting single-walled carbon nanotubes (SWCNTs) in electronic device applications such as thin-film transistors (TFTs). This workdemonstrates that Raman microscopy mapping is a powerful characterization tool for quantifying residual metallic carbon nanotubes present in highly enriched semiconducting nanotube networks. Raman mapping correlates well with absorption spectroscopy, yet it provides greater differentiation in purity. Electrical data from TFTs with channel lengths of 2.5 and 5 μm demonstrate the utility of the method. By comparing samples with nominal purities of 99.0% and 99.8%, a clear differentiation can be made when evaluating the current on/off ratio as a function of channel length, and thus the Raman mapping method provides a means to guide device fabrication by correlating SWCNT network density and purity with TFT channel scaling.
Tsinghua University Press
Zhao Li,Jianfu Ding,Paul Finnie,Jacques Lefebvre,Fuyong Cheng,Christopher T. Kingston,Patrick R. L. Malenfant, Raman microscopy mapping for the purity assessment of chirality enriched carbon nanotube networks in thin-film transistors. NanoRes.2015, 8(7): 2179–2187