scholarly journals Boosting the Power Factor of Benzodithiophene Based Donor–Acceptor Copolymers/SWCNTs Composites through Doping

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1447
Author(s):  
Zhongming Chen ◽  
Mengfei Lai ◽  
Lirong Cai ◽  
Wenqiao Zhou ◽  
Dexun Xie ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Power Factor ◽  
Room Temperature ◽  
Composite Films ◽  
Side Chain ◽  
Seebeck Coefficients ◽  
Electrical Conductivities ◽  
Before And After ◽  
Donor Acceptor ◽  
Walled Carbon Nanotubes

In this study, a benzodithiophene (BDT)-based donor (D)–acceptor (A) polymer containing carbazole segment in the side-chain was designed and synthesized and the thermoelectric composites with 50 wt % of single walled carbon nanotubes (SWCNTs) were prepared via ultrasonication method. Strong interfacial interactions existed in both of the composites before and after immersing into the 2,3,5,6-Tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) solution as confirmed by UV-Vis-NIR, Raman, XRD and SEM characterizations. After doping the composites by F4TCNQ, the electrical conductivity of the composites increased from 120.32 S cm−1 to 1044.92 S cm−1 in the room temperature. With increasing the temperature, the electrical conductivities and Seebeck coefficients of the undoped composites both decreased significantly for the composites; the power factor at 475 K was only 6.8 μW m−1 K−2, which was about nine times smaller than the power factor at room temperature (55.9 μW m−1 K−2). In the case of doped composites, although the electrical conductivity was deceased from 1044.9 S cm−1 to 504.17 S cm−1, the Seebeck coefficient increased from 23.76 μV K−1 to 35.69 μW m−1 K−2, therefore, the power factors of the doped composites were almost no change with heating the composite films.

scholarly journals Fabrication of PEDOT: PSS-PVP Nanofiber-Embedded Sb2Te3 Thermoelectric Films by Multi-Step Coating and Their Improved Thermoelectric Properties

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2835
Author(s):  
Sang-il Kim ◽  
Kang Yeol Lee ◽  
Jae-Hong Lim
Keyword(s):  
Thermoelectric Properties ◽  
Power Factor ◽  
Photoelectron Spectroscopy ◽  
Hybrid Composites ◽  
Composite Films ◽  
X Ray Diffraction ◽  
Thermoelectric Efficiency ◽  
X Ray ◽  
Seebeck Coefficients ◽  
Electrical Conductivities

Antimony telluride thin films display intrinsic thermoelectric properties at room temperature, although their Seebeck coefficients and electrical conductivities may be unsatisfactory. To address these issues, we designed composite films containing upper and lower Sb2Te3 layers encasing conductive poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS)- polyvinylpyrrolidone(PVP) nanowires. Thermoelectric Sb2Te3/PEDOT:PSS-PVP/Sb2Te3(ED) (STPPST) hybrid composite films were prepared by a multi-step coating process involving sputtering, electrospinning, and electrodeposition stages. The STPPST hybrid composites were characterized by field-emission scanning electron microscopy, X-ray diffraction, ultraviolet photoelectron spectroscopy, and infrared spectroscopy. The thermoelectric performance of the prepared STPPST hybrid composites, evaluated in terms of the power factor, electrical conductivity and Seebeck coefficient, demonstrated enhanced thermoelectric efficiency over a reference Sb2Te3 film. The performance of the composite Sb2Te3/PEDOT:PSS-PVP/Sb2Te3 film was greatly enhanced, with σ = 365 S/cm, S = 124 μV/K, and a power factor 563 μW/mK.

scholarly journals The Investigation of the Seebeck Effect of the Poly(3,4-Ethylenedioxythiophene)-Tosylate with the Various Concentrations of an Oxidant

Polymers ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 21 ◽  
Author(s):  
Joon-Soo Kim ◽  
Woongsik Jang ◽  
Dong Wang
Keyword(s):  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Power Factor ◽  
In Situ Polymerization ◽  
Seebeck Effect ◽  
Particle Sizes ◽  
Seebeck Coefficients ◽  
Optimal Power ◽  
Electrical Conductivities

Poly(3,4-ethylenedioxythiophene)-tosylate (PEDOT-Tos) can be synthesized through an in situ polymerization and doping process with iron(III) p-toluenesulfonate hexahydrate as an oxidant. Both the Seebeck coefficient and the electrical conductivity were modified by varying the concentration of the oxidant. We investigated the effects of varying the concentration of the oxidant on the particle sizes and doping (oxidation) levels of PEDOT-Tos for thermoelectric applications. We demonstrated that an increase in the oxidant enabled an expansion of the particle sizes and the doping levels of the PEDOT-Tos. The modification of the doping levels by the concentration of the oxidant can provide another approach for having an optimal power factor for thermoelectric applications. De-doping of PEDOTs by reduction agents has been generally investigated for changing its oxidation levels. In this study, we investigated the effect of the concentration of the oxidant of PEDOT-Tos on the oxidation levels, the electrical conductivities and the Seebeck coefficients. As loading the oxidant of PEDOT-Tos, the Seebeck coefficient was compromised, while the electrical conductivity increased.

Enhancing the Thermoelectric Performance through the Mutual Interaction between Conjugated Polyelectrolytes and Single-walled Carbon Nanotubes

2022 ◽  
Author(s):  
Shuxun Wan ◽  
Zhongming Chen ◽  
Liping Hao ◽  
Shichao Wang ◽  
Benzhang Li ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Thermoelectric Properties ◽  
Thermoelectric Generator ◽  
Composite Films ◽  
Single Walled Carbon Nanotubes ◽  
Conjugated Polyelectrolytes ◽  
High Performing ◽  
Single Walled Carbon ◽  
Electrical Conductivities ◽  
Walled Carbon Nanotubes

Abstract We present a method of constructing composites composed of conjugated polyelectrolytes (CPEs) and single-walled carbon nanotubes (SWCNTs) to obtain a high-performing flexible thermoelectric generator. In this approach, three kinds of polymers, namely, poly[(1,4-(2,5-didodecyloxybenzene)-alt-2,5-thiophene] (P1), poly[(1,4-(2,5-bis-sodium butoxysulfonate-phenylene)-alt-2,5-thiophene] (P2), and poly[(1,4-(2,5-bis-acid butoxysulfonic-phenylene)-alt-2,5-thiophene] (P3) are designed, synthesized and complexed with SWCNTs as thermoelectric composites. The electrical conductivities of CPEs/SWCNTs (P2/SWCNTs, and P3/SWCNTs) nanocomposites are much higher than those of non-CPEs/SWCNTs (P1/SWCNTs) nanocomposites. Among them, the electrical conductivity of P2/SWCNTs with a ratio of 1:4 reaches 3686 S cm-1, which is 12.4 times that of P1/SWCNTs at the same SWCNT mass ratio. Moreover, CPEs/SWCNTs composites (P2/SWCNTs) display remarkably improved thermoelectric properties with the highest power factor (PF) of 163 μW m-1 K-2. In addition, a thermoelectric generator is fabricated with P2/SWCNTs composite films, and the output power and power density of this generator reach 1.37 μW and 1.4 W m-2 (cross-section) at ΔT=70 K. This result is over three times that of the thermoelectric generator composed of non-CPEs/SWCNTs composite films (P1/SWCNTs, 0.37 μW). The remarkably improved electrical conductivities and thermoelectric properties of the CPEs/SWCNTs composites (P2/SWCNTs) are attributed to the enhanced interaction. This method for constructing CPEs/SWCNTs composites can be applied to produce thermoelectric materials and devices.

scholarly journals Preparation and Thermoelectric Properties of Semiconducting Single-Walled Carbon Nanotubes/Regioregular Poly(3-dodecylthiophene) Composite Films

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2720
Author(s):  
Mengdi Wang ◽  
Qin Yao ◽  
Sanyin Qu ◽  
Yanling Chen ◽  
Hui Li ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Transport Properties ◽  
Thermoelectric Properties ◽  
Composite Films ◽  
Single Walled Carbon Nanotubes ◽  
Dispersion Phase ◽  
Single Walled Carbon ◽  
Seebeck Coefficients ◽  
Regioregular Poly ◽  
Walled Carbon Nanotubes

Single-walled carbon nanotubes (SWNTs) have been widely used as leading additives for improving the thermoelectric properties of organic materials, due to their unique structure and excellent electronic transport properties. However, the as-synthesized SWNTs are mixtures (mix-SWNT) of semiconducting (sc-SWNT) and metallic (met-SWNT) carbon nanotubes. The significantly different surface character and transport behavior of sc-SWNT and met-SWNT frequently raise the difficulty of modifying microstructures, and tuning transport properties of SWNTs/organic composites, when using mix-SWNTs as dispersion phase. Herein, we prepared high quality sc-SWNTs/rr-P3DDT composite film by presorting pure sc-SWNT from the raw mix-SWNTs using regioregular poly(3-dodecylthiophene) (rr-P3DDT). Both the smoothness and compactness of sc-SWNTs/rr-P3DDT are great improved, as compared with the mix-SWNTs/rr-P3DDT films, and the sc-SWNTs are well-dispersed and uniformly wrapped by rr-P3DDT with diameter less than 50 nm. The significantly enhanced Seebeck coefficients and power factors are obtained in the sc-SWNT/rr-P3DDT samples. As the result, the maximum power factor of 60 μW/mK2 in 50 wt% sc-SWNTs sample is 70% higher than that of mix-SWNTs/P3DDT sample. This work reveals the effectiveness of pure semiconductor SWNTs as fillers to optimize the thermoelectric properties of CNT/polymer nano-composites.

Critical role of nanoinclusions in silver selenide nanocomposites as a promising room temperature thermoelectric material

2019 ◽  
Vol 7 (9) ◽  
pp. 2646-2652 ◽  
Author(s):  
Khak Ho Lim ◽  
Ka Wai Wong ◽  
Yu Liu ◽  
Yu Zhang ◽  
Doris Cadavid ◽  
...  
Keyword(s):  
Seebeck Coefficient ◽  
Room Temperature ◽  
Opposite Effect ◽  
Critical Role ◽  
Free Carrier ◽  
Silver Selenide ◽  
Band Bending ◽  
Seebeck Coefficients ◽  
Electrical Conductivities

The introduction of nonmetal nanoinclusions within Ag2Se results in an interphase band bending that promotes electron filtering and increase Seebeck coefficient. Similar loading of metal nanoinclusions provided an opposite effect-modulating free carrier concentration, as characterized by superior electrical conductivities and lower Seebeck coefficients.

scholarly journals Annealing Effect on the Thermoelectric Properties of Bi2Te3Thin Films Prepared by Thermal Evaporation Method

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Jyun-Min Lin ◽  
Ying-Chung Chen ◽  
Chi-Pi Lin
Keyword(s):  
Thin Films ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Thermal Evaporation ◽  
Thermal Evaporation Method ◽  
Si Substrates ◽  
Seebeck Coefficients

Bismuth telluride-based compounds are known to be the best thermoelectric materials within room temperature region, which exhibit potential applications in cooler or power generation. In this paper, thermal evaporation processes were adopted to fabricate the n-type Bi2Te3thin films on SiO2/Si substrates. The influence of thermal annealing on the microstructures and thermoelectric properties of Bi2Te3thin films was investigated in temperature range 100–250°C. The crystalline structures and morphologies were characterized by X-ray diffraction and field emission scanning electron microscope analyses. The Seebeck coefficients, electrical conductivity, and power factor were measured at room temperature. The experimental results showed that both the Seebeck coefficient and power factor were enhanced as the annealing temperature increased. When the annealing temperature increased to 250°C for 30 min, the Seebeck coefficient and power factor of n-type Bi2Te3-based thin films were found to be about −132.02 μV/K and 6.05 μW/cm·K2, respectively.

scholarly journals Light-Induced Sulfur Transport inside Single-Walled Carbon Nanotubes

Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 818 ◽  
Author(s):  
Olga Sedelnikova ◽  
Olga Gurova ◽  
Anna Makarova ◽  
Anastasiya Fedorenko ◽  
Anton Nikolenko ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Functional Properties ◽  
Single Walled Carbon Nanotubes ◽  
Acceptor Interaction ◽  
Local Composition ◽  
X Ray ◽  
Single Walled Carbon ◽  
Before And After ◽  
Donor Acceptor ◽  
Walled Carbon Nanotubes

Filling of single-walled carbon nanotubes (SWCNTs) and extraction of the encapsulated species from their cavities are perspective treatments for tuning the functional properties of SWCNT-based materials. Here, we have investigated sulfur-modified SWCNTs synthesized by the ampoule method. The morphology and chemical states of carbon and sulfur were analyzed by transmission electron microscopy, Raman scattering, thermogravimetric analysis, X-ray photoelectron and near-edge X-ray absorption fine structure spectroscopies. Successful encapsulation of sulfur inside SWCNTs cavities was demonstrated. The peculiarities of interactions of SWCNTs with encapsulated and external sulfur species were analyzed in details. In particular, the donor–acceptor interaction between encapsulated sulfur and host SWCNT is experimentally demonstrated. The sulfur-filled SWCNTs were continuously irradiated in situ with polychromatic photon beam of high intensity. Comparison of X-ray spectra of the samples before and after the treatment revealed sulfur transport from the interior to the surface of SWCNTs bundles, in particular extraction of sulfur from the SWCNT cavity. These results show that the moderate heating of filled nanotubes could be used to de-encapsulate the guest species tuning the local composition, and hence, the functional properties of SWCNT-based materials.

scholarly journals Electrospray characteristics of aqueous KCl solutions with various electrical conductivities

2018 ◽  
Author(s):  
Sahand Faraji ◽  
Behnam Sadri ◽  
Babak Vajdi Hokmabad ◽  
Esmaeil Esmaeilzadeh ◽  
Navid Jadidoleslam
Keyword(s):  
Electrical Conductivity ◽  
Experimental Study ◽  
Stainless Steel ◽  
High Voltage ◽  
Room Temperature ◽  
High Voltage Electrode ◽  
Flow Rates ◽  
Conductivity Variation ◽  
Electrical Conductivities ◽  
Stainless Steel Ring

In the present experimental study, the effects of electrical conductivity on electrospraying procedure are investigated.A metallic nozzle with 600 m ID as high voltage electrode and a stainless steel ring as a groundelectrode were employed. Experiments were carried out in still room temperature. Four different aqueous KClsolutions were sprayed in various high voltages and flow rates. Results confirm that spraying modes changeswith conductivity variation. For forming a cone shape, emerging from the nozzle, required applied electric fielddecreases with conductivity increasing. Results also revealed that conductivity of dispersed solution acts a mainrole on forming and elongation of the cones in electrospraying procedure. The size and velocity of emanateddroplets are also investigated in order to gaining some insight to the electrospraying phenomenon.

Thermoelectric Properties of CoSb3 Nanoparticle Films

2011 ◽  
Vol 347-353 ◽  
pp. 3448-3455
Author(s):  
Ya Jun Yang ◽  
Xian Yun Liu ◽  
Xu Dong Wang ◽  
Mei Ping Jiang ◽  
Xian Feng Chen ◽  
...  
Keyword(s):  
Thermoelectric Properties ◽  
Power Factor ◽  
Room Temperature ◽  
Maximum Power ◽  
Vapor Transport ◽  
Growth Technique ◽  
Highly Efficient ◽  
Nanoparticle Films ◽  
Electrical Conductivities ◽  
Maximum Power Factor

Cobblestone-like CoSb3 nanoparticle films have been achieved via a catalyst-free vapor transport growth technique. The thermoelectric properties of the nanoparticle films were measured from room temperature to around 500 oC. The resultant CoSb3 nanoparticle films show high electrical conductivities due to clean particle surfaces. A maximum power factor reaches 1.848×10−4 W/mK2 at 440 oC. The discussed approach is promising for realizing new types of highly efficient thermoelectric semiconductors.

A novel electrochemical sensor based on carbon nanoparticle composite films for the determination of nitrite and hydrogen peroxide

2016 ◽  
Vol 8 (21) ◽  
pp. 4204-4210 ◽  
Author(s):  
Shufang Li ◽  
Jianying Qu ◽  
Yong Wang ◽  
Jianhang Qu ◽  
Huijuan Wang
Keyword(s):  
Carbon Nanotubes ◽  
Hydrogen Peroxide ◽  
Electrochemical Sensor ◽  
Carbon Nanoparticles ◽  
Room Temperature ◽  
Composite Films ◽  
Carbon Nanoparticle ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Carbon nanoparticles (CNs) were successfully synthesized at room temperature, which were used to construct a novel electrochemical sensor combined with multi-walled carbon nanotubes and chitosan.

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