A strategy for enhancement of mechanical and electrical properties of polycarbonate/multi-walled carbon nanotube composites

Two poly(3-hexylthiophene)-g-polycaprolactones (P3HT-g-PCLs) with different degrees of polymerization (DP) of P3HT backbone were synthesized and used as a compatibilizer for bisphenol A polycarbonate (PC)/multi-walled carbon nanotube (MWCNT) composites. Both field emission-scanning electron microscopy and melt-state rheology show that MWCNTs are homogeneously dispersed in PC matrix when P3HT-g-PCL is added to PC/MWCNT composites. As a consequence, the mechanical and electrical properties of PC/MWCNT composites are dramatically improved when a small amount of P3HT-g-PCL is added to PC/MWCNT composites. It is also found that P3HT-g-PCL with lower DP of P3HT backbone is more effective to homogeneously disperse MWCNTs in PC matrix than that with higher DP of P3HT. This is because the π-π interaction between MWCNTs and P3HT-g-PCL with lower DP of P3HT is stronger than the case of P3HT with higher DP of P3HT, as evidenced by fluorescence emission spectra.     

Multi-walled carbon nanotubes covalently attached with poly(3-hexylthiophene) for enhancement of field-effect mobility of poly(3-hexylthiophene)/multi-walled carbon nanotube composites

For the purpose of enhancing the field-effect mobility of poly(3-hexylthiophene) (P3HT), multi-walled carbon nanotubes (MWCNTs) were functionalized by attaching covalently P3HT onto the MWCNT surface to yield P3HT-grafted MWCNTs (g-MWCNTs). When a small amount of g-MWCNTs was added to P3HT, the field-effect mobility of the composite was considerably increased as compared to either P3HT or the composites of P3HT and carboxylated MWCNTs (c-MWCNTs). This is because g-MWCNTs are better dispersed than c-MWCNTs in P3HT matrix and consequently g-MWCNTs act more effectively as conducting bridges connecting the crystallites of P3HT.     

Enhanced properties of phthalonitrile‐terminated polyarylene ether nitriles embedded with hybrid MWCNT–boehmite nanocomposites

The main motivation of the present work was to fabricate novel multifunctional polymer‐based nanocomposites. The nanocomposites embedded with multi‐walled carbon nanotube‐boehmite (MWCNT‐boehmite) were prepared via hot pressure casting technique. The MWCNT coated with boehmite were synthesized by hydrothermal synthesis. Subsequently, as‐prepared MWCNT‐boehmite was added into the phthalonitrile‐terminated polyarylene ether nitriles (PEN‐t‐CN) matrix in order to benefit from the synergetic effect of MWCNT and boehmite. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) X‐ray diffraction (XRD), and Fourier transform infrared (FTIR) were employed to confirm the existence of MWCNT‐boehmite in our article. Furthermore, the structures, fracture morphologies, thermal, mechanical and dielectric properties of the nanocomposites were investigated, respectively. SEM images indicated that the MWCNT‐boehmite was homogeneously dispersed in the polymer, which acted as an essential factor to ensure good physical properties. The TGA analysis showed that the incorporation of MWCNT‐boehmite enhanced the thermal stability of the nanocomposites with initial degradation temperature (T_id) increasing from 458 to 492°C, while that of the pure PEN‐t‐CN was 439°C. The mechanical testing proved that significant enhancement of mechanical properties has been achieved. The tensile strength of PEN‐t‐CN/MWCNT‐boehmite composites with 3 wt% MWCNT‐boehmite reached the maximum (78.33 MPa), with a 41.7 % increase compared to the pure polymer. More importantly, the unique dielectric properties were systematically discussed and the results demonstrated that dielectric properties exhibited little dependency on frequency. For the incorporation of hybrid filler, the positive impact of MWCNT‐boehmite hybrid material resulted in polymer‐based nanocomposites with enhanced physical properties. POLYM. COMPOS., 36:2193–2202, 2015. © 2014 Society of Plastics Engineers     

Release characteristics of selected carbon nanotube polymer composites

Multi-walled carbon nanotubes (MWCNTs) are commonly used in polymer formulations to improve strength, conductivity, and other attributes. A developing concern is the potential for carbon nanotube polymer nanocomposites to release nanoparticles into the environment as the polymer matrix degrades or is mechanically stressed. Here, we review characteristics related to release potential of five sets of polymer systems: epoxy, polyamide, polyurethane, polyethylene, and polycarbonate. Our review includes consideration of general characteristics and use of the polymer (as related to potential MWCNT release) and its MWCNT composites; general potential for nanomaterial release (particularly MWCNTs) due to degradation and mechanical stresses during use; and potential effects of stabilizers and plasticizers on polymer degradation. We examine UV degradation, temperature extremes, acid–base catalysis, and stresses such as sanding. Based on a high-level summary of the characteristics considered, the potential for release of MWCNT with typical, intended consumer use is expected to be low.     

Poly(3-hexylthiophene) wrapped carbon nanotube/poly(dimethylsiloxane) composites for use in finger-sensing piezoresistive pressure sensors

We fabricated a piezoresistive composite using multi-walled carbon nanotubes (MWCNTs) as a conductive filler and polydimethylsiloxane (PDMS) as a polymer matrix, which operated in the extremely small pressure range required for finger-sensing. To achieve a homogeneous dispersion of MWCNTs in PDMS, the MWCNTs were modified by a polymer wrapping method using poly(3-hexylthiophene) (P3HT). The percolation threshold of the composites was significantly lowered by the presence of P3HT. The electrical conductivity and piezoresistive sensitivity of the composite were found to strongly depend on the P3HT concentration. The well-dispersed P3HT-MWCNT/PDMS composite showed good piezoresistive characteristics in the 0–0.12 MPa pressure range.     

Self‐assembly of poly(3‐hexyl thiophene)‐b‐poly(ethylene oxide) into cylindrical micelles in binary solvent mixtures

Asymmetric block copolymer based on regioregular poly(3‐hexyl thiophene) (P3HT) and poly(ethylene oxide) (PEO) was synthesized through Heck reactions. The addition of PEO block has no influence in the effective conjugation length of P3HT block and apparently provides colloidal stability for the formation of stable nanostructures. Introduction of poor solvent to good solvent containing P3HT‐b‐PEO will induce the crystallization‐driven assembly of the P3HT into cylindrical micelles with a P3HT core, owing to π–π stacking of the conjugated backbone of P3HT. The absorption spectra of the cylindrical micelles reveal a red shift as compared to the polymer in good solvent, indicating the extension of conjugation length with an improved π–π stacking of the polymer chains within the cylindrical micelles. Our results indicated that cylindrical micelles with varied diameter and length can be obtained when solvent properties were varied using several different binary solvent mixtures. More interestingly, we demonstrate that ultrasonic processing can fragment the cylindrical micelles only when the ratio of poor solvent increases. This provides a facile and effective way to fabricate cylindrical micelles for applications in the area of polymer solar cell as well as organic optoelectronics device. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41186.     

Synthesis of hyperbranched polythiophenes containing tetrachloroperylene bisimide as bridging moiety for polymer solar cells

The goal of this research is to synthesize the hyperbranched polythiophene derivatives (P1 and P4) containing tetrachloroperylene bisimide as bridging moiety for investigation of thermal, electrochemical, and opto-electrical properties of these derivatives. The polymers (P2 and P3) containing soft alkyl spacer as bridging moiety and linear poly(3-hexylthiophene) (P3HT) were also synthesized for comparison in this study. Polymers with high regioregularity were synthesized via the Universal Grignard metathesis polymerization. The GPC results showed that molecular weights of hyperbranched polythiophenes are higher than that of P3HT. The TGA experiments revealed a first-stage weight loss at about 300 °C for all polymers; besides, polymers containing rigid tetrachloroperylene bisimide groups possess less weight loss than P3HT after heating, indicative of enhanced thermal stabilities. The UV–vis absorption maxima of hyperbranched polymers are similar to that of P3HT in film state, while their absorption shoulder bands are stronger than that of P3HT, indicating stronger interchain interaction and shorter distance between backbones by the introduction of bridge architecture. Moreover, an attenuation of fluorescent intensity was found for those hyperbranched polymers, implying reduced recombination of excitons to emit light and more opportunity for carriers to migrate to both electrodes. Electrochemical analysis showed that introducing hyperbranched structure resulted in decreasing both LUMO and HOMO levels of polymers. All polymers were used for fabrication of polymer solar cells with the configuration of ITO/PEDOT/polymer:PC₆₀BM (1:2 w/w)/LiF/Al to evaluate their performance. The power conversion efficiency (PCE) of the P3HT:PC₆₀BM-based device is 0.54%, while devices based on hyperbranched polymers showed PCE values in the range of 0.45–0.84%. The morphological study of polymer:PC₆₀BM blend films was performed by AFM for interpretation of efficiency trend of devices.     

Lead free CsSn0.5Ge0.5I3 perovskite solar cell with different layer properties via SCAPS-1D simulation

Organic–inorganic halide perovskite solar cells (PSCs) have been extensively studied due to their simple fabrication methods and obvious device efficiency advantages. In this work, the perovskite CsSn_0.5Ge_0.5I₃ is used as the light absorption layer, which is doped with Ge²⁺ in CsSnI₃ to improve its stability. The polymers of 3-hexylthiophene (P3HT) with excellent optoelectronic properties and low price, and SnO₂ with high electron extraction ability is selected as charge transport layers. Based on these, a novel PSC structure (FTO/SnO₂/IDL1/CsSn_0.5Ge_0.5I₃/IDL2/P3HT/Au) has been simulated via solar cell capacitor simulator (SCAPS-1D). The PSC performance is optimized by adjusting a series of parameters, including the layer thickness, defect density, electron affinity potential energy, and operating temperature, and so forth. The results show that the PSC defects are passivated by adjusting the appropriate parameters, and the final optimized open circuit voltage (V_OC) is 1.08 V, short-circuit current density (J_SC) is 27.37 mA/cm², fill factor (FF) is 83.32%, while the power conversion efficiency (PCE) is increased from the initial 10.89% to 24.63%, which provides theoretical reference for experiments and new ideas for the preparation and development of efficient and environmentally friendly PSCs. Finally, the effect of different metal cathodes with and without hole transport layer (HTL) on PSC performance is compared. The PSCs without HTL are more dependent on battery cathodes, which provided a way to replace precious metals with other electrode materials.     

Preparation of a poly(3‐hexylthiophene)‐grafted indium tin oxide/poly(3‐hexylthiopene) composite and its conductivity–temperature characteristics

The temperature–conductivity characteristics of poly(3‐hexylthiophene) (P3HT) composites filled with P3HT‐grafted indium tin oxide (ITO) particles were investigated in this work. The ITO particles were first treated with a silane coupling reagent of 3‐aminopropyltriethoxysilane (APS), and then thiophene rings were introduced through a condensation reaction between the ending amino groups of APS and the carboxylic groups of thiophene‐3‐acetic acid. The composites were prepared by the polymerization filling of the 3‐hexylthiophene (3HT) monomer with the thiophene‐ring‐introduced ITO particles. Elemental analysis, Fourier transform infrared, and X‐ray photoelectron spectroscopy were used to confirm the grafting reaction on the ITO surface. The longer the polymerization time was or the higher the 3HT/ITO feeding ratio was, the more P3HT was grafted. The influence of the grafted amount on the electrical properties of ITO particles was attributed to the wrapping effect formed by the grafted P3HT on the surface of the ITO particles. The conductivity change of the P3HT‐grafted ITO/P3HT composites was proved to be subject to the change in the average gap width of ITO interparticles, which was determined by the filling ratio of P3HT to ITO in the polymerization and the volume expansion effect of a P3HT thin film between neighboring ITO particles during the heating process. In comparison with the ungrafted ITO/P3HT composites, the grafting treatment enhanced the interaction between the particles and polymer matrix, and this was helpful for obtaining a more homogeneous dispersion structure for the composites and thus afforded a higher positive temperature coefficient intensity and better reproducibility. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1881–1888, 2006     

One-pot synthesis of poly-(3-hexylthiophene) with variable degrees of molar mass and regioregularity

Polyalkylthiophenes are applied in the form of thin films as active layers in organic devices. The main properties defined in the synthetic procedure that can affect the film formation are the molar mass and regioregularity degree (the content of head-to-tail, HT, linkages). These properties can be varied, at principle, by changing the conditions of the oxidative polymerization process. In this work, we evaluate the effect of oxidant addition rate, temperature and time-dependence of poly-(3-hexylthiophene), P3HT, oxidative polymerization in molar mass and regioregularity degree, besides other polymer properties such as absorption and emission of visible light. The results show that the polymer started to grow during the oxidant addition and already presents a relatively high molar mass (ca. 10,000 g/mol) just after the addition stopped. Polymerization temperature is more significant in molar mass variations than the time expended for the polymerization reaction, with values of Mw ranging from 15,000 to 70,000 g/mol in the conditions tested. The HT contents were all above 70 %, with higher variations in the two first hours of polymerization reaction and are mainly defined during the oxidant addition, which leads to higher HT contents and narrower molar mass distributions using slower additions. The solvent extraction reveals that the HT content is directly related to the polymer chains extension, being possible to improve both regioregularity degree and molar mass of P3HT.     

Influence of applying microwave radiation on the LDPE/MWCNTs nanocomposite

Low density polyethylene (LDPE) and multiwall carbon nanotube (MWCNT) nanocomposites of varying MWCNT contents were prepared by melt blending and compression molding. The sample sheets were exposed to microwave irradiation and the effect on chemical, mechanical, and thermal properties as well as the sheets' morphology were determined and compared with that of nonirradiated samples with similar compositions. The percentage crystallinity of the LDPE/MWCNT nanocomposites declined after irradiation due to the degradation of polymeric chains. However, the melting temperature was hardly changed. The chemical degradation due to irradiation was also verified from the increase in the carbonyl index as determined from the Fourier transformed‐infrared spectroscopy study and the decline in the storage modulus of the dynamic mechanical analysis study. The microcalorimetry study revealed that the MWCNT nanofillers were effectively acting as a heat absorption shield by reducing the heat release rate of polymer during combustion. The Raman spectra and scanning electron microscopy photographs demonstrated improved interaction of MWCNT with the LDPE matrix after microwave irradiation. POLYM. COMPOS., 35:2036–2042, 2014. © 2014 Society of Plastics Engineers     

Thermal and mechanical properties of homogeneous ternary nanocomposites of regioregular poly(3‐hexylthiophene)‐wrapped multiwalled carbon nanotube dispersed in thermoplastic polyurethane: Dynamic‐ and thermomechanical analysis

An interesting correlation between initial loading and nature of wrapping of regioregular poly(3‐hexylthiophene) (rrP3HT) on multiwalled carbon nanotube and their combined effect on dynamic‐ and thermomechanical properties in ternary system (thermoplastic polyurethane as matrix) is highlighted. Wrapping of rrP3HT on carbon nanotube (CNT) makes the hexyl side chains thermally nonequivalent and composites more stable. Dynamic‐ and thermomechanical analysis ascertained the miscibility (single T_g = ?40°C), large mechanical reinforcement, and improved storage modulus of nanocomposites in the presence of CNT compared to its blends. Two breaks at ～ ?100 and ～ ?40°C for TPU‐P3HT composites (PHs) and TPU‐P3HT‐MWCNT composites (PHCs) in the loss modulus vs. temperature plot indicates two different types of transitions in P3HT chains. Dimensional stability by expansion probe technique measures low coefficient of thermal expansion of PHCs compared to its blends. Softening property by penetration probe technique suggests that 2.5 wt % loading of P3HT exhibits lowest degree of penetration compared to other nanocomposites. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Influence of wrapping on some properties of MWCNT–PMMA and MWCNT–PE composites

The melt processing technique was used to elaborate composites made with a polymer matrix [polymethylmethacrylate (PMMA) or polyethylene (PE)] and multiwall carbon nanotubes (MWCNT). Nanotubes were wrapped by amphiphilic block copolymer (PE–co-polyethylene oxide) in aqueous solution to facilitate the dispersion and the handling. Morphology and physical properties (thermal, mechanical, electrical, and rheological) of the resulting composites were investigated. The wrapping of MWCNT allowed a good dispersion of these nanoparticules in the polymer matrices. Physical properties such as thermal degradation, mechanical behavior, and conduction are improved. The use of wrapped MWCNT allows to reduce drastically the melt viscosity of the blends of crystalline PE composites whereas it is almost non efficient for amorphous PMMA ones.     

The effect of multiwalled carbon nanotube dimensions on the morphology,mechanical, and electrical properties of melt mixed polypropylene‐based composites

The effect of multiwalled carbon nanotube (MWCNT) dimensions and surface modification on the morphology, mechanical reinforcement, and electrical properties of PP‐based composites, prepared by melt mixing, has been studied. The MWCNTs of small (d < 10 nm) and large (d = 40–60 nm) diameters with various intrinsic aspect ratios (L/d) have been used as filler. Transmission electron microscopy and very cold neutrons (VCN) scattering showed that both as‐received and surface modified small diameter MWCNT(1)s exhibit a strong tendency to bundle or cluster together in melt compared to both long MWCNT(3)s and short MWCNT(2)s large diameter nanotubes. The fractions of isolated nanotubes are higher and the mass‐fractal dimensions are lower for thick MWCNT‐based nanocomposites. The nanotubes of all types are heterogeneous nucleation sites for PP crystallization. The tensile and DMA testing results revealed that both long thick MWCNT(3)s with L/d ≈ 300 and thin MWCNT(1)s with highest intrinsic L/d > 1000 exhibit similar reinforcing effects, because drastically decreasing the effective aspect ratio (L/d)_eff of the thin flexibly nanotubes within polymer matrix. The nanocomposites based on the long large diameter MWCNT(3)s demonstrated the lowest percolation threshold equal to 1.5 vol % loading, highest dielectric and electromagnetic waves shielding properties. It was concluded that the choice of optimal diameter and length of MWCNTs is right approach to the improvement in the dispersion state and straightness of multiwelled carbon nanotubes in polymer melt as well as to enhancement of their efficiency as reinforcing and conductive nanosized filler. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Influence of aminosilane‐functionalized carbon nanotubes on the rheometric,mechanical, electrical and thermal degradation properties of epoxidized natural rubber nanocomposites

We describe the preparation, characterization and physical properties of multiwalled carbon nanotube (MWCNT)‐filled epoxidized natural rubber (ENR) composites. To ensure better dispersion in the elastomer matrix, the MWCNTs were initially subjected to aminopropyltriethoxysilane (APS) treatment to bind amine functional groups (?NH₂) on the nanotube surface. Successful grafting of APS on the MWCNT surface through Si–O–C linkages was confirmed using Fourier transform infrared spectroscopy. Grafting of APS on the MWCNT surface was further corroborated using elemental analysis. ENR nanocomposites with various filler loadings were prepared by melt compounding to generate pristine and APS‐modified MWCNT‐filled elastomeric systems. Furthermore, we determined the effects of various filler loadings on the rheometric, mechanical, electrical and thermal degradation properties of the resultant composite materials. Rheometric cure characterization revealed that the torque difference increased with pristine MWCNT loading compared to the gum system, and this effect was more pronounced when silane‐functionalized MWCNTs were loaded, indicating that this effect was due to an increase in polymer–carbon nanotube interactions in the MWCNT‐loaded materials. Loading of silane‐functionalized MWCNTs in the ENR matrix resulted in a significant improvement in the mechanical, electrical and thermal degradation properties of the composite materials, when compared to gum or pristine MWCNT‐loaded materials.© 2013 Society of Chemical Industry     

Preparation of porous poly(3‐hexylthiophene) by freeze‐dry method and its application to organic photovoltaics

Poly(3‐hexylthiophene)(P3HT) with a microporous network structure was prepared from a 1% p‐xylene solution by freeze‐dry method. Scanning electron microscopy (SEM) showed P3HT molecules formed swollen gel‐like structures with different extent of compactness depending on the length of the aggregation period. Absorption spectrum of this P3HT film showed a characteristic peak at 620 nm, which indicated a high degree of order between polymer chains. Photoluminescence (PL) of this highly ordered P3HT film appeared at 712 nm revealing large extent of π–π stacking between P3HT molecules in the freeze‐dry film. Both absorption and photoluminescence results indicated that the original aggregated states of P3HT molecules in gel form had been preserved throughout the freeze‐dry operation. X‐ray diffraction of the annealed samples showed a strong characteristic peak for the side chain aggregation at 2θ = 5.1°, which proved that the freeze‐dry film was with highly order structure. The interconnected and highly ordered P3HT film is used in the study of organic photovoltaics (OPV) after applying an n‐type semiconductor to the surface of the dry porous fibers. A prototype OPV device with power conversion efficiency of 1.47% was prepared by this method. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

Photoelectric Properties of Silicon Nanocrystals/P3HT Bulk-Heterojunction Ordered in Titanium Dioxide Nanotube Arrays

A silicon nanocrystals (Si-ncs) conjugated-polymer-based bulk-heterojunction represents a promising approach for low-cost hybrid solar cells. In this contribution, the bulk-heterojunction is based on Si-ncs prepared by electrochemical etching and poly(3-hexylthiophene) (P3HT) polymer. Photoelectric properties in parallel and vertical device-like configuration were investigated. Electronic interaction between the polymer and surfactant-free Si-ncs is achieved. Temperature-dependent photoluminescence and transport properties were studied and the ratio between the photo- and dark-conductivity of 1.7 was achieved at ambient conditions. Furthermore the porous titanium dioxide (TiO₂) nanotubes’ template was used for vertical order of photosensitive Si-ncs/P3HT-based blend. The anodization of titanium foil in ethylene glycol-based electrolyte containing fluoride ions and subsequent thermal annealing were used to prepare anatase TiO₂ nanotube arrays. The arrays with nanotube inner diameter of 90 and 50 nm were used for vertical ordering of the Si-ncs/P3HT bulk-heterojunction.     

Chitosan/P3HT biohybrid films as polymer matrices for the in-situ synthesis of CdSe quantum dots. Experimental and theoretical studies

Biohybrid nanocomposite films were obtained through a simple two-step methodology. Films of chitosan/poly(3-hexylthiophene) (CS/P3HT) were used as polymer matrices for the in-situ synthesis and stabilization of CdSe quantum dots. The biohybrid materials were characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), Raman spectroscopy, UV–visible spectroscopy, thermogravimetric analysis (TGA), field emission scanning electron microscope (FESEM), high-resolution transmission electron microscopy (HRTEM), and photoluminescence spectroscopy (PL). The effects of the P3HT composition on the properties of the QDs in the films were analyzed. The results confirmed that CS/P3HT films provided an adequately confining matrix for the growth of CdSe QDs with a fairly uniform size and revealed that the interactions between the CdSe nanoparticles and the CS/P3HT matrix mainly involved the  OH and  NH₂ groups. The optical band gaps of the biohybrid nanocomposite films were estimated. The results of photoluminescence revealed that a charge transfer phenomenon occurred in the polymer system. Finally, theoretical analyses suggest that the CdSe QDs would be preferentially located onto the chitosan domains.     

Enhanced device performance using different carbon nanotube types in polymer photovoltaic devices

The effects of incorporating different types of carbon nanotubes (single-walled, SWCNT; double-walled, DWCNT; and multi-walled carbon nanotubes, MWCNT) in organic solar cells were studied. Different compositions of carbon nanotubes in poly(3-hexiltiophene) (P3HT) were investigated. Absorption spectroscopy, photoluminescence and current–voltage measurements using 10 mW/cm² white light illumination in air, were carried out to determine the photovoltaic behaviour of the organic solar cells prepared. The addition of carbon nanotubes (CNTs) to the polymer increases the power conversion efficiency by three orders of magnitude compared with the device without CNTs, but there is no clear connection with the number of walls or diameter of the nanotubes. A critical concentration value of 5 wt.% of CNT is found to achieve the highest open-circuit voltage and the best performance for the majority of the CNTs studied.     

Synthesis and photovoltaic properties of two-dimensional conjugated polythiophene derivatives presenting conjugated triphenylamine/thiophene moieties

In this study we synthesized three two-dimensional (2-D) polythiophene derivatives (PTs), namely PTBPTPA, PTStTPA, and PTCNStTPA, featuring three different conjugated units—biphenyl (BP), stilbene (St), and cyanostilbene (CNSt), respectively—in the polymer backbones and presenting conjugated triphenylamine/thiophene (TPATh) moieties on the side chains. In addition, we also synthesized three conjugated BP-, St-, and CNSt-based main-chain-type conjugated polymers (PTBP, PTSt, and PTCNSt, respectively). Incorporating the St and CNSt moieties into the polymer backbones and appending TPATh units induced high degrees of intramolecular charge transfer within the conjugated frameworks of the polymers, thereby resulting in lower band gap energies and red-shifting of the maximal UV–Vis absorption wavelengths. Moreover, the energy levels of the highest occupied molecular orbitals of the BP-, St-, and CNSt-based main-chain-type and 2-D PTs were lower than that of P3HT, implying that they would be applicable for the preparation of polymer solar cells (PSC) with greater open-circuit voltages. The photovoltaic performances of PSCs fabricated from blends of the 2-D PTs and the fullerene derivative PC₆₁BM were superior to those of PSCs based on the main-chain-type polymer/PC₆₁BM blends.