Improvement of Transparent Conducting Nanotube Films by Addition of Small Quantities of Graphene

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• 作者：Paul J. King ; Umar Khan ; Mustafa Lotya ; Sukanta De ; Jonathan N. Coleman
• 刊名：ACS Nano
• 出版年：2010
• 出版时间：July 27, 2010
• 年：2010
• 卷：4
• 期：7
• 页码：4238-4246
• 全文大小：476K
• 年卷期：0
• ISSN：1936-086X

文摘

We demonstrate a water-based method to prepare transparent, conducting graphene/single-walled nanotube hybrid films. While the transmittance decreases slightly with increasing graphene content, the DC conductivity, σ_DC, and sheet resistance scale non-monotonically with film composition. We observe an optimum composition of ∼3 wt % graphene, which results in a peak in the DC conductivity. We have calculated the figure of merit, the DC to optical conductivity ratio, σ_DC/σ_Op, which also shows a peak at this composition. We find that this effect is only present for small graphene flakes. In addition, acid treatment increases both the σ_DC and σ_DC/σ_Op by ×2.5. Interestingly, acid treatment is more effective for films close to the optimum composition. This has the effect of sharpening the peaks in both σ_DC and σ_DC/σ_Op. For acid-treated films, addition of 3 wt % graphene results in a 40% increase in σ_DC/σ_Op compared to the nanotube-only film, from 12.5 to 18. Optimized, acid-treated films display transmittance of 80% coupled with a sheet resistance of 100 Ω/◻.