Charge Transport in Mixed Semiconducting Carbon Nanotube Networks with Tailored Mixing Ratios
| Autor: | Stefan P. Schießl, Maik Matthiesen, Felix J. Berger, Maximilian Brohmann, Severin Schneider, Jana Zaumseil |
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| Rok vydání: | 2019 |
| Předmět: |
Nanotube
Materials science business.industry Ambipolar diffusion General Engineering General Physics and Astronomy 02 engineering and technology Carbon nanotube Electron 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences law.invention Semiconductor law Plasma torch Optoelectronics General Materials Science Charge carrier Field-effect transistor 0210 nano-technology business |
| Zdroj: | ACS Nano. 13:7323-7332 |
| ISSN: | 1936-086X 1936-0851 |
| Popis: | The ability to prepare uniform and dense networks of purely semiconducting single-walled carbon nanotubes (SWNTs) has enabled the design of various (opto-)electronic devices, especially field-effect transistors (FETs) with high carrier mobilities. Further optimization of these SWNT networks is desired to surpass established solution-processable semiconductors. The average diameter and diameter distribution of nanotubes in a dense network were found to influence the overall charge carrier mobility; e.g., networks with a broad range of SWNT diameters show inferior transport properties. Here, we investigate charge transport in FETs with nanotube networks comprising polymer-sorted small diameter (6,5) SWNTs (0.76 nm) and large diameter plasma torch SWNTs (1.17-1.55 nm) in defined mixing ratios. All transistors show balanced ambipolar transport with high on/off current ratios and negligible hysteresis. While the range of bandgaps in these networks creates a highly uneven energy landscape for charge carrier hopping, the extracted hole and electron mobilities vary nonlinearly with the network composition from the lowest mobility (15 cm2 V-1 s-1) for only (6,5) SWNT to the highest mobility (30 cm2 V-1 s-1) for only plasma torch SWNTs. A comparison to numerically simulated network mobilities shows that a superposition of thermally activated hopping across SWNT-SWNT junctions and diameter-dependent intratube transport is required to reproduce the experimental data. These results also emphasize the need for monochiral large diameter nanotubes for maximum carrier mobilities in random networks. |
| Databáze: | OpenAIRE |
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