The Molecular Weight Dependence of Thermoelectric Properties of Poly (3-Hexylthiophene)

Mardi, Saeed; Pea, Marialilia; Notargiacomo, A.; Nia, Narges Yaghoobi; Carlo, Aldo Di; Reale, Andrea

doi:10.3390/ma13061404

Cited by 21 publications

(12 citation statements)

References 48 publications

(52 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The UV–Vis and PL spectra of the diluted solutions and pristine films of all P3ATs with various MWs are shown in Figure 4 . The maxima of the UV–Vis spectra originate from the π-π* transitions, which are typical for the π-conjugated P3ATs, as discussed in previous studies [ 37 , 41 , 56 ]. The first common tendency is that both the UV–Vis and PL spectra of the films are significantly red-shifted to those of the solutions after solidification.…”

Section: Resultssupporting

confidence: 54%

“…The MW of P3ATs may affect their optical properties [ 38 ], solid-state morphologies [ 31 , 39 ], crystallinity [ 40 ] and hole mobility [ 41 ], and therefore, the physical and photoelectric properties of the P3AT-based devices. However, various trends of MW dependence have been observed, probably because of various experimental conditions and the complexity of the studied object; therefore, conflicting MW effects in conjunction with the side-chain effects on device performance have been reported.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Molecular Weight-Dependent Physical and Photovoltaic Properties of Poly(3-alkylthiophene)s with Butyl, Hexyl, and Octyl Side-Chains

Nguyen

Song

et al. 2021

Polymers

View full text Add to dashboard Cite

A series of poly-3-alkylthiophenes (P3ATs) with butyl (P3BT), hexyl (P3HT), and octyl (P3OT) sidechains and well-defined molecular weights (MWs) were synthesized using Grignard metathesis polymerization. The MWs of P3HTs and P3OTs obtained via gel permeation chromatography agreed well with the calculated MWs ranging from approximately 10 to 70 kDa. Differential scanning calorimetry results showed that the crystalline melting temperature increased with increasing MWs and decreasing alkyl side-chain length, whereas the crystallinity of the P3ATs increased with the growth of MWs. An MW-dependent red shift was observed in the UV–Vis and photoluminiscence spectra of the P3ATs in solution, which might be a strong evidence for the extended effective conjugation occurring in polymers with longer chain lengths. The photoluminescence quantum yields of pristine films in all polymers were lower than those of the diluted solutions, whereas they were higher than those of the phenyl-C61-butyric acid methyl ester-blended films. The UV–Vis spectra of the films showed fine structures with pronounced red shifts, and the interchain interaction-induced features were weakly dependent on the MW but significantly dependent on the alkyl side-chain length. The photovoltaic device performances of the P3BT and P3HT samples significantly improved upon blending with a fullerene derivative and subsequent annealing, whereas those of P3OTs mostly degraded, particularly after annealing. The optimal power conversion efficiencies of P3BT, P3HT, and P3OT were 2.4%, 3.6%, and 1.5%, respectively, after annealing with MWs of ~11, ~39, and ~38 kDa, respectively.

show abstract

Section: Resultssupporting

confidence: 54%

Section: Introductionmentioning

confidence: 99%

Molecular Weight-Dependent Physical and Photovoltaic Properties of Poly(3-alkylthiophene)s with Butyl, Hexyl, and Octyl Side-Chains

Nguyen

Song

et al. 2021

Polymers

View full text Add to dashboard Cite

show abstract

“…A considerable amount of research has focused on the structure–property relationship of semiconducting polymers interacting with 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ), a conjugated small-molecule dopant. − Schwartz’s group designed a series of dodecaborane (DDB)-based dopants with large size and different shapes, which could effectively shield a doped conjugated polymer from Coulombic interaction with dopant counterions to improve the doping efficiency and carrier mobility. In addition, the molecular weight of polymers also relates to the film mobility associated with the microstructure and connectivity of the crystalline domains. ,− Wegner et al found that P3HT with high molecular weight shows a high degree of crystallinity beneficial to transport properties . Besides organic-conjugated molecules as dopants, inorganic salt-type dopants generally induce higher doping efficiency than that of F4TCNQ because of their stronger oxidation properties. − For instance, ferric salts, such as FeCl 3 and Fe(III) triflimide, are successfully used to oxidize p-type thiophene polymers. ,, The doping process of inorganic salts induces dopant counterions (anions) left into the film interacting with polymer chains.…”

Section: Introductionmentioning

confidence: 99%

Anion-Dependent Molecular Doping and Charge Transport in Ferric Salt-Doped P3HT for Thermoelectric Application

Chai

et al. 2021

ACS Appl. Electron. Mater.

View full text Add to dashboard Cite

The effect of different iron (III) dopants on the doping process and charge transport properties based on a poly(3hexylthiophene) (P3HT) film was investigated. It is found that the doping level is dependent on not only the driving force for charge transfer but also the miscibility between a polymer and a dopant, while the mobile carrier transport is significantly controlled by the microstructure upon doping. A high electrical conductivity (128 S cm −1 ) is obtained for a FeCl 3 -doped P3HT film among three different doped P3HT combinations, although a low doping level is observed in this film. In contrast, a highest doping level but a low electrical conductivity (65 S cm −1 ) is achieved for Fe(OTf) 3 -doped P3HT. Another ferric salt with a larger size anion and strong oxidation ability, Fe(Tos) 3 , endows both much low doping level and low electrical conductivity (9 S cm −1 ). Grazing-incidence wide-angle X-ray scattering (GIWAXS) shows that a much stronger π−π stacking of P3HT and larger crystalline domains may exist in Fe(OTf) 3 -doped P3HT compared with those of FeCl 3 -doped P3HT. However, Hall-effect measurements show that the high electrical conductivity of FeCl 3 -doped P3HT is mainly attributed to higher carrier mobility. Temperature-dependent conductivity experiments demonstrate that smaller activation energy for carrier transport is needed for a FeCl 3 -doped P3HT film. These results indicate that smooth and continuous transport paths are formed in a FeCl 3doped film, contributing to high carrier mobility while discrete domains in Fe(OTf) 3 -doped film hamper the carrier transport. A prototype device with a five-leg FeCl 3 -doped P3HT film connected with a silver paste was fabricated. The measured maximum output power is about 4.64 nW at the temperature difference of 23.3 K. Our results suggest that the interaction between dopant anions and polymer chains is crucial for high electrical conductivity by improving morphologies to achieve ionized carriers' transfer into much mobile carriers.

show abstract

“…Aiming at replacing spiro-OMeTAD, different polymers are being investigated for application in PSCs, also because of the possibility to adjust their properties by acting on their molecular weight (MW). − Among these, a suitable candidate is poly(3-hexylthiophene) (P3HT), a material that has seen vast application in the field of organic photovoltaics (OPVs) as a donor polymer in bulk-heterojunction solar cells, thermoelectric applications, and organic light-emitting devices (OLEDs). P3HT has attracted great interest as a polymeric hole-selective material for PSCs due to its scalable solution processability, high thermal stability, low cost, relatively high hole mobility (0.1 cm 2 V –1 s –1 ), oxygen impermeability, wide band-gap, and robust hydrophobicity …”

Section: Introductionmentioning

confidence: 99%

Impact of P3HT Regioregularity and Molecular Weight on the Efficiency and Stability of Perovskite Solar Cells

Nia

Bonomo

Zendehdel

et al. 2021

ACS Sustainable Chem. Eng.

Self Cite

View full text Add to dashboard Cite

The commercialization of perovskite solar cells (PSCs) has seen an important limitation in the instability that afflicts the hole-transporting layer (HTL), namely, spiro-OMeTAD, used in high-efficiency devices. The latter is, in turn, relatively expensive, undermining the sustainability of the device. Its replacement with polymeric scaffolds, such as poly(3hexylthiophene) (P3HT), will solve these issues. In this work, we adopted various sustainable synthetic methods to obtain four different homemade P3HTs with different molecular weights (MWs) and regioregularities (RRs), leading to different structural properties. They are implemented as HTLs in PSCs, and the effect of their properties on the efficiency and thermal stability of devices is thoroughly discussed. The highest efficiency is obtained with the highest MW and low-RR polymer (17.6%) owing to the more sustainable approach, but a very promising value is also reached with a lower-MW but fully regioregular polymer (15%). Finally, large-area devices with an efficiency of 16.7%, fabricated with a high-MW P3HT, show more than 1000 h (T80 = 1108 h) of stability under accelerated thermal stress tests (85 °C) out of glovebox while keeping over 85% of the initial efficiency of an unencapsulated device after more than 3000 min under continuous light soaking (AM 1.5G).

show abstract

The Molecular Weight Dependence of Thermoelectric Properties of Poly (3-Hexylthiophene)

Cited by 21 publications

References 48 publications

Molecular Weight-Dependent Physical and Photovoltaic Properties of Poly(3-alkylthiophene)s with Butyl, Hexyl, and Octyl Side-Chains

Molecular Weight-Dependent Physical and Photovoltaic Properties of Poly(3-alkylthiophene)s with Butyl, Hexyl, and Octyl Side-Chains

Anion-Dependent Molecular Doping and Charge Transport in Ferric Salt-Doped P3HT for Thermoelectric Application

Impact of P3HT Regioregularity and Molecular Weight on the Efficiency and Stability of Perovskite Solar Cells

Contact Info

Product

Resources

About