Cu-ion-induced n- to p-type switching in organic thermoelectric polyazacycloalkane/carbon nanotubes

Abstract

The semiconducting properties of polyazacycloalkane/carbon nanotubes film can be changed from n-type to p-type by Cu ions, which simplifies module manufacturing.

Synergistic Interactions in Sequential Process Doping of Polymer/Single‐Walled Carbon Nanotube Nanocomposites for Enhanced n‐Type Thermoelectric Performance

“…There, the intensity of the RBM band is seen to decrease as the doping concentration of N‐DMBI is increased in both the NDI‐T1/SWCNT and NDI‐T2/SWCNT nanocomposites (Figure S3a,b, Supporting Information), thereby indicating the effective adsorption of N‐DMBI onto the surfaces of the SWCNTs. [ 28 ] In the case of the IID‐T2/SWCNT, however, no consistent trend in the intensity of the RBM band with doping concentration is observed (Figure S3c, Supporting Information), thereby indicating that the interaction between the N‐DMBI and SWCNTs is weaker than that between the IID‐T2 and the SWCNTs. These results are consistent with the abovementioned PL and UV–vis–NIR spectra, which indicated strong interactions between the IID‐T2 and SWCNTs.…”

“…[24,25] Pristine CNTs typically exhibit p-type thermoelectric behavior due to their susceptibility to oxygen doping during the synthesis process and storage. [26,27] However, several viable methods have been developed to transform CNTs into n-type thermoelectric materials, including ionic doping using polyelectrolyte dispersion agents or ionic liquids, [28][29][30] or treatment with reducing agents such as hydrazine, [31,32] calcium hydride, [33] or sodium borohydride, [34] or with aminecontaining organic molecules such as polyethylenimine, [17] diethylenetriamine, [33,35] and 4-(2,3-dihydro-1,3-dimethyl-1Hbenzimidazol-2-yl)-N,N-dimethylbenzenamine (N-DMBI). [36,37] In particular, the small molecule N-DMBI stands out due to its compatibility with both conjugated polymers and SWC-NTs, which enables the simultaneous doping of the polymer and SWCNT components of the hybrid nanocomposite with N-DMBI to obtain remarkable n-type thermoelectric performance.…”

Water‐resistant organic thermoelectric generator with >10 μW output

“…32 The CNTs act as p-type conductors in the presence of water or oxygen 33 and the assembly of both p-and n-type materials is instrumental for efficient TE conversion. 34 Dopants that direct CNT carriers from pto n-type in air are widely prepared; these include NaBH 4 , 35 cobaltocene, 36 polyethyleneimine, 37 and polyvinyl alcohol. 38 CNTs with a two-component dopant system of alkali salts and crown ethers are ideal thermodynamically stable n-type materials that maintain n-type properties for more than 30 days at 423 K in air.…”

“…Recently, several effective strategies have been proposed to improve the TE performance of CNT‐based materials by compositing with metal nanoparticles 30,31 or polymer complexes 32 . The CNTs act as p‐type conductors in the presence of water or oxygen 33 and the assembly of both p‐ and n‐type materials is instrumental for efficient TE conversion 34 . Dopants that direct CNT carriers from p‐ to n‐type in air are widely prepared; these include NaBH 4 , 35 cobaltocene, 36 polyethyleneimine, 37 and polyvinyl alcohol 38 .…”

Ambient-Stable n-Type Carbon Nanotube/Organic Small-Molecule Thermoelectrics Enabled by Energy Level Control

“…Recently, n-type organic thermoelectric materials based on carbon nanotubes have garnered attention owing to their lightweight nature, mechanical strength, and exceptional electrical properties. Aliphatic amines, such as triethylamine, 1,4,7,10-tetraazacyclododecane, diethylenetriamine (DETA), and amino acids, are typically used as reducing agents to produce n-type carbon nanotubes. – However, their relatively wide bandgaps (>5.0 eV) can cause the lifting of the LUMOs (or conduction bands) of n-type carbon nanotube composites, which may decrease their air stability.…”