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Intrinsic electrical conductivity of nanostructured metal-organic polymer chains.

Hermosa C, Vicente Álvarez J, Azani MR, Gómez-García CJ, Fritz M, Soler JM, Gómez-Herrero J, Gómez-Navarro C, Zamora F - Nat Commun (2013)

Bottom Line: This magnitude is preserved for distances as large as 300 nm.We provide the first direct experimental evidence of the gapless electronic structure predicted for these compounds.Our results postulate metal-organic molecular wires as good metallic interconnectors in nanodevices.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Química Inorgánica, Universidad Autónoma de Madrid, Madrid 28049, Spain.

ABSTRACT
One-dimensional conductive polymers are attractive materials because of their potential in flexible and transparent electronics. Despite years of research, on the macro- and nano-scale, structural disorder represents the major hurdle in achieving high conductivities. Here we report measurements of highly ordered metal-organic nanoribbons, whose intrinsic (defect-free) conductivity is found to be 10(4) S m(-1), three orders of magnitude higher than that of our macroscopic crystals. This magnitude is preserved for distances as large as 300 nm. Above this length, the presence of structural defects (~ 0.5%) gives rise to an inter-fibre-mediated charge transport similar to that of macroscopic crystals. We provide the first direct experimental evidence of the gapless electronic structure predicted for these compounds. Our results postulate metal-organic molecular wires as good metallic interconnectors in nanodevices.

No MeSH data available.


Growth of nanoribbons with high degree of structural perfection by crystal sublimation.(a) Structure of a [Pt2(dta)4I]n (dta=dithioacetato) single fibre. (b,c,d) AFM images of nanoribbons on a SiO2 substrate where the straightness and height homogeneity can be appreciated. The inset in d is a profile acquired on the green line of the corresponding image, where the cross-section of the ribbons can be determined. Typical dimensions of the nanoribbons are 10 μm × 100 nm × 20 nm. Scale bars, 8, 4 and 0.1 μm (for b, c and d, respectively).
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f1: Growth of nanoribbons with high degree of structural perfection by crystal sublimation.(a) Structure of a [Pt2(dta)4I]n (dta=dithioacetato) single fibre. (b,c,d) AFM images of nanoribbons on a SiO2 substrate where the straightness and height homogeneity can be appreciated. The inset in d is a profile acquired on the green line of the corresponding image, where the cross-section of the ribbons can be determined. Typical dimensions of the nanoribbons are 10 μm × 100 nm × 20 nm. Scale bars, 8, 4 and 0.1 μm (for b, c and d, respectively).

Mentions: Figure 1a provides a schematic representation of a single chain of [Pt2(dta)4I]n. The crystals were synthesized and characterized as described in Bellitto et al.23 The nanoribbons were prepared by sublimating these crystals under high vacuum conditions on SiO2(300 nm)/Si(100) substrates previously treated with oxygen plasma (details can be found in the Methods section and Supplementary Figs S1 and S2). AFM images of the resulting nanoribbons are shown in Fig. 1b–d. Subsequent to nanoribbon growth, a macroscopic electrode was deposited by thermal evaporation of gold using a convenient stencil mask. The final result is a long gold electrode edge that partially covers a number of nanoribbons. The electrical resistance of the nanostructure was probed by CAFM2526. Figure 2a shows a representative AFM image of a nanoribbon protruding from a gold electrode, and a scheme of the electrical circuit was used to characterize the ribbon. Figure 2c displays the electrical resistance R, as a function of the distance between electrodes L, obtained for a representative nanoribbon. The resistance displays an initial region where it barely depends on length followed by a rapid increase that can be fitted well to an exponential law. The current versus voltage (I/V) curves acquired for the nanoribbons and depicted in Fig. 2b show a linear dependence, and hence the resistance for each data point in Fig. 2c is independent of the bias voltage.


Intrinsic electrical conductivity of nanostructured metal-organic polymer chains.

Hermosa C, Vicente Álvarez J, Azani MR, Gómez-García CJ, Fritz M, Soler JM, Gómez-Herrero J, Gómez-Navarro C, Zamora F - Nat Commun (2013)

Growth of nanoribbons with high degree of structural perfection by crystal sublimation.(a) Structure of a [Pt2(dta)4I]n (dta=dithioacetato) single fibre. (b,c,d) AFM images of nanoribbons on a SiO2 substrate where the straightness and height homogeneity can be appreciated. The inset in d is a profile acquired on the green line of the corresponding image, where the cross-section of the ribbons can be determined. Typical dimensions of the nanoribbons are 10 μm × 100 nm × 20 nm. Scale bars, 8, 4 and 0.1 μm (for b, c and d, respectively).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3644075&req=5

f1: Growth of nanoribbons with high degree of structural perfection by crystal sublimation.(a) Structure of a [Pt2(dta)4I]n (dta=dithioacetato) single fibre. (b,c,d) AFM images of nanoribbons on a SiO2 substrate where the straightness and height homogeneity can be appreciated. The inset in d is a profile acquired on the green line of the corresponding image, where the cross-section of the ribbons can be determined. Typical dimensions of the nanoribbons are 10 μm × 100 nm × 20 nm. Scale bars, 8, 4 and 0.1 μm (for b, c and d, respectively).
Mentions: Figure 1a provides a schematic representation of a single chain of [Pt2(dta)4I]n. The crystals were synthesized and characterized as described in Bellitto et al.23 The nanoribbons were prepared by sublimating these crystals under high vacuum conditions on SiO2(300 nm)/Si(100) substrates previously treated with oxygen plasma (details can be found in the Methods section and Supplementary Figs S1 and S2). AFM images of the resulting nanoribbons are shown in Fig. 1b–d. Subsequent to nanoribbon growth, a macroscopic electrode was deposited by thermal evaporation of gold using a convenient stencil mask. The final result is a long gold electrode edge that partially covers a number of nanoribbons. The electrical resistance of the nanostructure was probed by CAFM2526. Figure 2a shows a representative AFM image of a nanoribbon protruding from a gold electrode, and a scheme of the electrical circuit was used to characterize the ribbon. Figure 2c displays the electrical resistance R, as a function of the distance between electrodes L, obtained for a representative nanoribbon. The resistance displays an initial region where it barely depends on length followed by a rapid increase that can be fitted well to an exponential law. The current versus voltage (I/V) curves acquired for the nanoribbons and depicted in Fig. 2b show a linear dependence, and hence the resistance for each data point in Fig. 2c is independent of the bias voltage.

Bottom Line: This magnitude is preserved for distances as large as 300 nm.We provide the first direct experimental evidence of the gapless electronic structure predicted for these compounds.Our results postulate metal-organic molecular wires as good metallic interconnectors in nanodevices.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Química Inorgánica, Universidad Autónoma de Madrid, Madrid 28049, Spain.

ABSTRACT
One-dimensional conductive polymers are attractive materials because of their potential in flexible and transparent electronics. Despite years of research, on the macro- and nano-scale, structural disorder represents the major hurdle in achieving high conductivities. Here we report measurements of highly ordered metal-organic nanoribbons, whose intrinsic (defect-free) conductivity is found to be 10(4) S m(-1), three orders of magnitude higher than that of our macroscopic crystals. This magnitude is preserved for distances as large as 300 nm. Above this length, the presence of structural defects (~ 0.5%) gives rise to an inter-fibre-mediated charge transport similar to that of macroscopic crystals. We provide the first direct experimental evidence of the gapless electronic structure predicted for these compounds. Our results postulate metal-organic molecular wires as good metallic interconnectors in nanodevices.

No MeSH data available.