Metallic films, sheet resistance substrates

Yang and co-workers used the separated metallic SWNTs in a systematic evaluation on transparent conductive films, which also included nanotubes from different sources coupled with various fabrication conditions. It is worth noting that the films were on a flexible substrate (PET), for which dip coating was used. Again, those films from the separated metallic SWNTs exhibited sheet resistance down to 130 Q sq for 80% optical transmittance at 550 nm (Table 6.1). The comparison of nanotube films with ITO coatings on the... 

In another study, Maeda et al fabricated transparent conductive films by air spraying enriched metallic SWNTs (from the amine-assisted post-production separation ) on to both quartz and PET substrates. The sheet resistances in the films on PET were 690 Q sq at an optical transmittance of 81% (550 nm) and 9000 Q sq at 97% (550 nm), which represented reductions by a factor of 20 in comparison with the performance in films of non-separated SWNTs. The same group also found that the effectiveness in the separation for metallic SWNTs is determined by the use of different amines at various concentrations. The proportion of metallic SWNTs against semiconducting SWNTs in the... 

The separated metallic S WCNTs were also found to enhance transparent conductive performance in composite films with conductive polymers, particularly the poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOTPSS) blend as it is optically transparent in the visible spectral region (Figure 16.20). In such composites, the conductive polymer blend served the function of dispersion agents, so no surfactants were necessary in the film fabrication. In the work by Wang et al, suspensions of nanotubes (enriched metallic or nonseparated S WCNTs) in DMSO were mixed with aqueous PEDOTPSS in various compositions, and the resulting mixtures were sprayed outo au optically transparent substrate. The sheet resistance results demonstrated that the composite films with enriched metallic SWCNTs were consistently and substantially better in performance than those with nonseparated SWCNTs (and both better than films with neat PEDOTPSS). Aqueous PEDOTPSS is not as effective as commonly used surfactants in the dispersion of SWCNTs, which... 

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