Ammonia Plasma-Induced n-Type Doping of Semiconducting Carbon Nanotube Films: Thermoelectric Properties and Ambient Effects

Liu, Ye; Nitschke, Mirko; Stepien, Lukas; Khavrus, Vyacheslav O.; Bezugly, Viktor; Cuniberti, Gianaurelio

doi:10.1021/acsami.9b02918

Cited by 17 publications

(23 citation statements)

References 38 publications

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“…Thin films were produced to demonstrate the thermoelectric properties of the SWCNTs themselves, as described in Liu et al [29]. In detail, either pristine SWCNTs or B-SWCNTs (1 wt%) were dispersed in water with addition of 0.1 wt% of sodium cholate as surfactants (sodium cholate hydrate, >99%, Sigma-Aldrich, St. Louis, MO, USA).…”

Section: Methodsmentioning

confidence: 99%

Boron Doping of SWCNTs as a Way to Enhance the Thermoelectric Properties of Melt-Mixed Polypropylene/SWCNT Composites

et al. 2020

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Composites based on the matrix polymer polypropylene (PP) filled with single-walled carbon nanotubes (SWCNTs) and boron-doped SWCNTs (B-SWCNTs) were prepared by melt-mixing to analyze the influence of boron doping of SWCNTs on the thermoelectric properties of these nanocomposites. It was found that besides a significantly higher Seebeck coefficient of B-SWCNT films and powder packages, the values for B-SWCNT incorporated in PP were higher than those for SWCNTs. Due to the higher electrical conductivity and the higher Seebeck coefficients of B-SWCNTs, the power factor (PF) and the figure of merit (ZT) were also higher for the PP/B-SWCNT composites. The highest value achieved in this study was a Seebeck coefficient of 59.7 µV/K for PP with 0.5 wt% B-SWCNT compared to 47.9 µV/K for SWCNTs at the same filling level. The highest PF was 0.78 µW/(m·K2) for PP with 7.5 wt% B-SWCNT. SWCNT macro- and microdispersions were found to be similar in both composite types, as was the very low electrical percolation threshold between 0.075 and 0.1 wt% SWCNT. At loadings between 0.5 and 2.0 wt%, B-SWCNT-based composites have one order of magnitude higher electrical conductivity than those based on SWCNT. The crystallization behavior of PP is more strongly influenced by B-SWCNTs since their composites have higher crystallization temperatures than composites with SWCNTs at a comparable degree of crystallinity. Boron doping of SWCNTs is therefore a suitable way to improve the electrical and thermoelectric properties of composites.

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Section: Methodsmentioning

confidence: 99%

Boron Doping of SWCNTs as a Way to Enhance the Thermoelectric Properties of Melt-Mixed Polypropylene/SWCNT Composites

et al. 2020

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“…Liu et al. [ 97 ] investigated the semiconducting properties of single‐walled carbon nanotubes (sc‐SWCNTs) with covalent functionalization after ammonia plasma treatment, achieving a high and positive Seebeck coefficient by adsorbing H 2 O or O 2 as p‐dopants. These sc‐SWCNT films achieved n‐type doping under NH 3 plasmas, as proven by XPS, leading to lower Seebeck coefficient values of 40 µV K −1 at ambient conditions due to competing effects between the electron‐donating functional groups and adsorption of H 2 O.…”

Section: Effect Of Discharge Gas On Cbmsmentioning

confidence: 99%

Advance in Using Plasma Technology for Modification or Fabrication of Carbon‐Based Materials and Their Applications in Environmental, Material, and Energy Fields

Sun

Bao

et al. 2020

Adv Funct Materials

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Plasma technology is an eco‐friendly way to modify or fabricate carbon‐based materials (CBMs) due to plasmas’ distinctive abilities in tuning the surface physicochemical properties by implanting functional groups or incorporating heteroatoms into the surface without changing the bulk structure. However, the mechanisms of functional groups formation on the carbon surface are still not clearly explained because of the variety of different discharge conditions and the complexity of plasma chemistry. Consequently, this paper contains a comprehensive review of plasma‐treated carbon‐based materials and their applications in environmental, materials, and energy fields. Plasma‐treated CBMs used in these fields have been significantly enhanced in recent years because these related materials possess unique features after plasma treatment, such as higher adsorption capacity, enhanced wettability, improved electrocatalytic activity, etc. Meanwhile, this paper also summarizes possible reaction routes for the generation of functional groups on CBMs. The outlook for future research is summarized, with suggestions that plasma technology research and development shall attempt to achieve precise control of plasmas to synthesize or to modify CBMs at the atomic level.

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“…The n-type doping of CNTs is challenging, especially in terms of stability. Different approaches for CNT-doping are described, such as CNT functionalization, polymer wrapping, charge transfer from a polymer matrix to the CNTs, encapsulation of organometallic materials within the nanotubes, doping by salt anions with counter cations, or heteroatom incorporation into the CNT walls [11][12][13][14][15][16]. Concerning the stability of the doping, further processing such as annealing, purification or incorporation into polymer matrices also plays an important role.…”

Section: Introductionmentioning

confidence: 99%

Nitrogen-Doped Carbon Nanotube/Polypropylene Composites with Negative Seebeck Coefficient

et al. 2020

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This study describes the application of multi-walled carbon nanotubes that were nitrogen-doped during their synthesis (N-MWCNTs) in melt-mixed polypropylene (PP) composites. Different types of N-MWCNTs, synthesized using different methods, were used and compared. Four of the five MWCNT grades showed negative Seebeck coefficients (S), indicating n-type charge carrier behavior. All prepared composites (with a concentration between 2 and 7.5 wt% N-MWCNTs) also showed negative S values, which in most cases had a higher negative value than the corresponding nanotubes. The S values achieved were between 1.0 μV/K and −13.8 μV/K for the N-MWCNT buckypapers or powders and between −4.7 μV/K and −22.8 μV/K for the corresponding composites. With a higher content of N-MWCNTs, the increase in electrical conductivity led to increasing values of the power factor (PF) despite the unstable behavior of the Seebeck coefficient. The highest power factor was achieved with 4 wt% N-MWCNT, where a suitable combination of high electrical conductivity and acceptable Seebeck coefficient led to a PF value of 6.1 × 10−3 µW/(m·K2). First experiments have shown that transient absorption spectroscopy (TAS) is a useful tool to study the carrier transfer process in CNTs in composites and to correlate it with the Seebeck coefficient.

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Ammonia Plasma-Induced n-Type Doping of Semiconducting Carbon Nanotube Films: Thermoelectric Properties and Ambient Effects

Cited by 17 publications

References 38 publications

Boron Doping of SWCNTs as a Way to Enhance the Thermoelectric Properties of Melt-Mixed Polypropylene/SWCNT Composites

Boron Doping of SWCNTs as a Way to Enhance the Thermoelectric Properties of Melt-Mixed Polypropylene/SWCNT Composites

Advance in Using Plasma Technology for Modification or Fabrication of Carbon‐Based Materials and Their Applications in Environmental, Material, and Energy Fields

Nitrogen-Doped Carbon Nanotube/Polypropylene Composites with Negative Seebeck Coefficient

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