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Organic nanofibers integrated by transfer technique in field-effect transistor devices.

Tavares L, Kjelstrup-Hansen J, Thilsing-Hansen K, Rubahn HG - Nanoscale Res Lett (2011)

Bottom Line: Bottom contact devices are dominated by contact effects, while the top contact device characteristics are determined by the nanofiber bulk properties.It is found that the contact resistance is lower for crystalline nanofibers when compared to amorphous thin films.These results shed light on the charge injection and transport properties for such organic nanostructures and thus constitute a significant step forward toward a nanofiber-based light-emitting device.

View Article: PubMed Central - HTML - PubMed

Affiliation: NanoSYD, Mads Clausen Institute, University of Southern Denmark, Alsion 2, DK-6400 S√łnderborg, Denmark. tavares@mci.sdu.dk.

ABSTRACT
The electrical properties of self-assembled organic crystalline nanofibers are studied by integrating these on field-effect transistor platforms using both top and bottom contact configurations. In the staggered geometries, where the nanofibers are sandwiched between the gate and the source-drain electrodes, a better electrical conduction is observed when compared to the coplanar geometry where the nanofibers are placed over the gate and the source-drain electrodes. Qualitatively different output characteristics were observed for top and bottom contact devices reflecting the significantly different contact resistances. Bottom contact devices are dominated by contact effects, while the top contact device characteristics are determined by the nanofiber bulk properties. It is found that the contact resistance is lower for crystalline nanofibers when compared to amorphous thin films. These results shed light on the charge injection and transport properties for such organic nanostructures and thus constitute a significant step forward toward a nanofiber-based light-emitting device.

No MeSH data available.


Related in: MedlinePlus

Measured transistor characteristics for BC/BG nanofibers. (a) Current versus gate voltage for Vds = -15 V. Inset shows schematic Mott-Schottky energy scheme for negative gate and drain voltages. (b) Current versus drain-source voltage for zero gate voltage. Arrows indicate the sweep direction. Inset shows energy level positions: the work function level for the gold drain and source electrodes (5.1 eV) and the LUMO (3.0 eV) and HOMO (6.0 eV) levels for p6P. (c) Mott-Schottky energy scheme for zero gate voltage and negative drain voltage. (d) Mott-Schottky energy scheme for zero gate voltage and positive drain voltage.
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Figure 3: Measured transistor characteristics for BC/BG nanofibers. (a) Current versus gate voltage for Vds = -15 V. Inset shows schematic Mott-Schottky energy scheme for negative gate and drain voltages. (b) Current versus drain-source voltage for zero gate voltage. Arrows indicate the sweep direction. Inset shows energy level positions: the work function level for the gold drain and source electrodes (5.1 eV) and the LUMO (3.0 eV) and HOMO (6.0 eV) levels for p6P. (c) Mott-Schottky energy scheme for zero gate voltage and negative drain voltage. (d) Mott-Schottky energy scheme for zero gate voltage and positive drain voltage.

Mentions: Figure 3a shows the measured transfer characteristics, i.e., current versus gate voltage for a drain-source voltage of -15 V for p6P nanofibers on a BC/BG device. The inset in Figure 3a is the Mott-Schottky energy scheme at negative gate and drain voltages which, however, do not account for interface traps states that could further reduce the current. The source-drain field allows only holes injected from the source electrode or electrons injected from the drain electrode to pass through the device and the measured characteristics clearly show that the transport is p-type, i.e., holes are injected from the source (see Figure 3a inset).


Organic nanofibers integrated by transfer technique in field-effect transistor devices.

Tavares L, Kjelstrup-Hansen J, Thilsing-Hansen K, Rubahn HG - Nanoscale Res Lett (2011)

Measured transistor characteristics for BC/BG nanofibers. (a) Current versus gate voltage for Vds = -15 V. Inset shows schematic Mott-Schottky energy scheme for negative gate and drain voltages. (b) Current versus drain-source voltage for zero gate voltage. Arrows indicate the sweep direction. Inset shows energy level positions: the work function level for the gold drain and source electrodes (5.1 eV) and the LUMO (3.0 eV) and HOMO (6.0 eV) levels for p6P. (c) Mott-Schottky energy scheme for zero gate voltage and negative drain voltage. (d) Mott-Schottky energy scheme for zero gate voltage and positive drain voltage.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211406&req=5

Figure 3: Measured transistor characteristics for BC/BG nanofibers. (a) Current versus gate voltage for Vds = -15 V. Inset shows schematic Mott-Schottky energy scheme for negative gate and drain voltages. (b) Current versus drain-source voltage for zero gate voltage. Arrows indicate the sweep direction. Inset shows energy level positions: the work function level for the gold drain and source electrodes (5.1 eV) and the LUMO (3.0 eV) and HOMO (6.0 eV) levels for p6P. (c) Mott-Schottky energy scheme for zero gate voltage and negative drain voltage. (d) Mott-Schottky energy scheme for zero gate voltage and positive drain voltage.
Mentions: Figure 3a shows the measured transfer characteristics, i.e., current versus gate voltage for a drain-source voltage of -15 V for p6P nanofibers on a BC/BG device. The inset in Figure 3a is the Mott-Schottky energy scheme at negative gate and drain voltages which, however, do not account for interface traps states that could further reduce the current. The source-drain field allows only holes injected from the source electrode or electrons injected from the drain electrode to pass through the device and the measured characteristics clearly show that the transport is p-type, i.e., holes are injected from the source (see Figure 3a inset).

Bottom Line: Bottom contact devices are dominated by contact effects, while the top contact device characteristics are determined by the nanofiber bulk properties.It is found that the contact resistance is lower for crystalline nanofibers when compared to amorphous thin films.These results shed light on the charge injection and transport properties for such organic nanostructures and thus constitute a significant step forward toward a nanofiber-based light-emitting device.

View Article: PubMed Central - HTML - PubMed

Affiliation: NanoSYD, Mads Clausen Institute, University of Southern Denmark, Alsion 2, DK-6400 S√łnderborg, Denmark. tavares@mci.sdu.dk.

ABSTRACT
The electrical properties of self-assembled organic crystalline nanofibers are studied by integrating these on field-effect transistor platforms using both top and bottom contact configurations. In the staggered geometries, where the nanofibers are sandwiched between the gate and the source-drain electrodes, a better electrical conduction is observed when compared to the coplanar geometry where the nanofibers are placed over the gate and the source-drain electrodes. Qualitatively different output characteristics were observed for top and bottom contact devices reflecting the significantly different contact resistances. Bottom contact devices are dominated by contact effects, while the top contact device characteristics are determined by the nanofiber bulk properties. It is found that the contact resistance is lower for crystalline nanofibers when compared to amorphous thin films. These results shed light on the charge injection and transport properties for such organic nanostructures and thus constitute a significant step forward toward a nanofiber-based light-emitting device.

No MeSH data available.


Related in: MedlinePlus