Gas phase doping of pre-fabricated CNT yarns for enhanced thermoelectric properties

Carbon Nanotube/Biomolecule Composite Yarn for Wearable Thermoelectric Applications

“…However, in general, the conductivity and the Seebeck coefficient of semiconductors are inversely proportional, whereas this result revealed a proportional relationship . The result in Figure could be explained by the fact that the yarn is in the low carrier concentration region, where σ and α increase simultaneously and α is sensitive to a small amount of dopant . In this case, the surfactant and/or C-Dps may work as weak dopants.…”

“…30 The result in Figure 3 could be explained by the fact that the yarn is in the low carrier concentration region, where σ and α increase simultaneously and α is sensitive to a small amount of dopant. 31 In this case, the surfactant and/or C-Dps may work as weak dopants. As a result, a higher power factor was achieved in CNT/C-Dps yarns with method D (Figure 3c).…”

Eco-friendly conversion between n- and p-type carbon nanotubes based on rationally functionalized lignin biopolymers

“…Fossil-fuel based organic dopants like carbazole and 7,7,8,8-tetracyanoquinodimethane (TCNQ) as p-dopants, and 1,3-bis(diphenylphosphino)propane (dppp) and polyethyleneimine (PEI) as n-dopants have mainly been used for surface charge transfer doping of CNT. [25][26][27][28][29] As an alternative to fossil fuel-based dopants, organosolv lignin (OL) was phenolated via a simple microwave method because the addition of phenol groups creates more reaction sites and achieves sufficiently high solubility for uniform, reliable, and efficient CNT doping. To create effective n-and p-dopants, phenolated lignin was further functionalized with diethylamine and hexafluoropropyl groups, respectively.…”

Influence of halogen elements in organic salts on n-type doping of CNT yarn for thermoelectric applications

“…1). [20][21][22][23][24][25] For example, Ali et al 20 and Myint et al 21 reported a charge transfer method by adding 2,3,5,6-tetrauoro-tetracyanoquinodimethane (F4TCNQ) into CNT and show good p-type TE performance due to the charge transfer from the CNT's valence band maximum (VBM) to the lower LUMO level of the dopant (Fig. 1(a1)).…”

“…An innovative pathway is a yarn-type sample of which the advantages are not only the exibility, [41][42][43] but also the ability for a millimetre-order-thick exible device which is easy to obtain large temperature difference even by natural air cooling, as demonstrated in previous studies. 11,15,20 CNT yarns also hold benets in the complex device design in the integrated fabrics. 15,44 Therefore, it is worthwhile to develop a strategy to effectively optimize the thermoelectric properties of CNT yarns.…”