Enhanced Charge Transport in ZnO Nanocomposite Through Interface Control Using Multiwall Carbon Nanotubes

Nam, Woo Hyun; Kim, Bo Bae; Lim, Young Soo; Seo, Won‐Seon; Park, Hyung Ho; Lee, Jun Young

doi:10.1111/jace.14198

Cited by 10 publications

(2 citation statements)

References 28 publications

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“…Because there is no depletion layer among Bi 2 Te 3 grains and CNT, regarding the PEF nanocomposite film, CNT would increase the carrier mobility as carrier migration channels. [ 60 ] The PEF treatment decreases the carrier concentration while it increases the carrier mobility. In addition, this kind of nanocomposite film may have additional features because the nanocomposite substrate was prepared in the air environment.…”

Section: Results and Analysismentioning

confidence: 99%

Thermoelectric Performance Enhancement of Film by Pulse Electric Field and Multi‐Nanocomposite Strategy

Liu

Lan

et al. 2021

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Thermoelectric (TE) film has wide potential application in low‐grade waste heat recovery and TE generation due to its quick response and multifunctional integration. Multi‐nanocomposite is a promising method to solve the difficulty of maintaining temperature difference and achieving a high figure of merit ZT. However, the depletion layer induced by the multi‐nanocomposite typically degrades performance. This study presents a simple and convenient method to solve this problem by pulse electric field (PEF). Prototypical TE Bi2Te3 is selected as the objective film. The strong current density effect of PEF removes the depletion layer among carbon nanotubes (CNT) and Bi2Te3 grains. Thus, the CNT nanocomposite with PEF treatment breaks the trade‐off between electrical conductivity and Seebeck coefficient, achieving a power factor of 4400 µW m−1 K−2 which stabilizes after annealing effect to 2920 µW m−1 K−2, a record for Bi2Te3 films. Simultaneously, the self‐assembled porosity decreases thermal conductivity via phonon scattering while still maintaining a high electrical conductivity of 3130 S cm−1. Thus, the porosity helps maintain the temperature difference and thereby enables a sharp increase in output power. These results indicate that the combination of PEF and multi‐nanocomposite is a new method to enhance TE performance, which would have a potential application in the commercial field.

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Section: Results and Analysismentioning

confidence: 99%

Thermoelectric Performance Enhancement of Film by Pulse Electric Field and Multi‐Nanocomposite Strategy

Liu

Lan

et al. 2021

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“…These samples include three categories: (1) CNTs/ZnO composite powers synthesized by using commercial CNTs combined with ultrasonic dispersion (named as 2.0% CNTs/ZnO); (2) ZnO powders with 2.0 wt% Ni catalysts grown on the surface (named as 2.0% Ni/ZnO); and (3) ZnO powders with in-situ grown CNTs using different loading contents of Ni catalysts. It is shown that the main patterns of all samples can be indexed to the wurtzite structure of ZnO (PDF#36-1451)[40]. Sharp diffraction peaks of ZnO can be obviously seen in all samples, indicating good crystallinity.…”

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confidence: 93%

In-situ growth of carbon nanotubes on ZnO to enhance thermoelectric and mechanical properties

et al. 2022

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As a high-temperature thermoelectric (TE) material, ZnO offers advantages of non-toxicity, chemical stability, and oxidation resistance, and shows considerable promise as a true ready-to-use module under air conditions. However, poor electrical conductivity and high thermal conductivity severely hinder its application. Carbon nanotubes (CNTs) are often used as a reinforcing phase in composites, but it is difficult to achieve uniform dispersion of CNTs due to van der Waals forces. Herein, we developed an effective in-situ growth strategy of homogeneous CNTs on ZnO nanoparticles by exploiting the chemical vapor deposition (CVD) technology, in order to improve their electrical conductivity and mechanical properties, as well as reducing the thermal conductivity. Meanwhile, magnetic nickel (Ni) nanoparticles are introduced as catalysts for promoting the formation of CNTs, which can also enhance the electrical and thermal transportation of ZnO matrices. Notably, the electrical conductivity of ZnO is significantly boosted from 26 to 79 S·cm−1 due to the formation of dense and uniform conductive CNT networks. The lattice thermal conductivity (κL) is obviously declined by the intensification of phonon scattering, resulting from the abundant grain boundaries and interfaces in ZnO-CNT composites. Importantly, the maximum dimensionless figure of merit (zT) of 0.04 at 800 K is obtained in 2.0% Ni-CNTs/ZnO, which is three times larger than that of CNTs/ZnO prepared by traditional ultrasonic method. In addition, the mechanical properties of composites including Vickers hardness (HV) and fracture toughness (KIC) are also reinforced. This work provides a valuable reference for dispersing nano-phases in TE materials to enhance both TE and mechanical properties.

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Breaking the tradeoff among thermoelectric parameters by multi composite of porosity and CNT in AZO films

Liu

Lan

et al. 2021

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Enhanced Charge Transport in ZnO Nanocomposite Through Interface Control Using Multiwall Carbon Nanotubes

Cited by 10 publications

References 28 publications

Thermoelectric Performance Enhancement of Film by Pulse Electric Field and Multi‐Nanocomposite Strategy

Thermoelectric Performance Enhancement of Film by Pulse Electric Field and Multi‐Nanocomposite Strategy

In-situ growth of carbon nanotubes on ZnO to enhance thermoelectric and mechanical properties

Breaking the tradeoff among thermoelectric parameters by multi composite of porosity and CNT in AZO films

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