Charge and thermoelectric transport in polymer-sorted semiconducting single-walled carbon nanotube networks
Understanding the charge transport mechanisms in chirality-selected single-walled carbon nanotube (SWCNT) networks and the influence of network parameters is essential for further advances of their optoelectronic and thermoelectric applications. Here, we report on charge density and temperature-depe...
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| Main Authors: | , , , , , , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
November 9, 2020
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| In: |
ACS nano
Year: 2020, Volume: 14, Issue: 11, Pages: 15552-15565 |
| ISSN: | 1936-086X |
| DOI: | 10.1021/acsnano.0c06181 |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1021/acsnano.0c06181
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| Author Notes: | Martin Statz, Severin Schneider, Felix J. Berger, Lianglun Lai, William A. Wood, Mojtaba Abdi-Jalebi, Simone Leingang, Hans-Jörg Himmel, Jana Zaumseil, and Henning Sirringhaus |
| Summary: | Understanding the charge transport mechanisms in chirality-selected single-walled carbon nanotube (SWCNT) networks and the influence of network parameters is essential for further advances of their optoelectronic and thermoelectric applications. Here, we report on charge density and temperature-dependent field-effect mobility and on-chip field-effect-modulated Seebeck coefficient measurements of polymer-sorted monochiral small-diameter (6,5) (0.76 nm) and mixed large-diameter SWCNT (1.17-1.55 nm) networks (plasma torch nanotubes, RN) with different network densities and length distributions. All untreated networks display balanced ambipolar transport and electron-hole symmetric Seebeck coefficients. We show that charge and thermoelectric transport in SWCNT networks can be modeled by the Boltzmann transport formalism, incorporating transport in heterogeneous media and fluctuation-induced tunneling. Considering the diameter-dependent one-dimensional density of states (DoS) of the SWCNTs composing the network, we can simulate the charge density and temperature-dependent Seebeck coefficients. Our simulations suggest that scattering in these networks cannot be described as simple one-dimensional acoustic and optical phonon scattering as for single SWCNTs. Instead the relaxation time is inversely proportional to energy (τ ∝ (E - EC)s, s = −1, EC being the energy of the first van Hove singularity), presumably pointing toward the more two-dimensional character of scattering events and the necessity to include scattering at the SWCNT junctions. Finally, our observation of higher power factors in trap-free, 1,2,4,5-tetrakis(tetramethylguanidino)benzene-treated (6,5) networks than in the RN networks emphasizes the importance of chirality selection to tune the width of the DoS. To benefit from both higher intrinsic mobilities and a large thermally accessible DoS, we propose trap-free, narrow DoS distribution, large-diameter SWCNT networks for both electronic and thermoelectric applications. |
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| Item Description: | Gesehen am 02.04.2022 |
| Physical Description: | Online Resource |
| ISSN: | 1936-086X |
| DOI: | 10.1021/acsnano.0c06181 |