Oriented Thin Films of Insoluble Polythiophene Prepared by the Friction Transfer Technique

A thin film of unsubstituted polythiophene (PT), an insoluble conjugated polymer, with molecular chains uniaxially oriented in plane was prepared by the friction transfer method. The structure of highly oriented thin films of PT was investigated using grazing-incidence X-ray diffraction (GIXD), ultraviolet–visible (UV–vis) spectroscopy, and infrared (IR) spectroscopy. The polarized UV–vis and IR spectra and GIXD measurements showed the PT molecular chains were well aligned in parallel to the friction direction. The GIXD studies clarified that the polymer backbones were aligned with very narrow distribution, such that the half-width was about 4 degrees. The degree of orientation of the PT friction-transferred film was higher compared with those of regioregular poly(3-alkylthiophene)s. Moreover, the GIXD results show a preferred orientation where the a-axis is perpendicular to the substrate plane.

The Influence of Reaction Time on Non-Covalent Functionalisation of P3HT/MWCNT Nanocomposites

Non-covalent functionalisation of the carbon nanotube (CNT) sidewall through polymer wrapping is the key strategy for improving well-dispersed CNTs without persistent alteration of their electronic properties. In this work, the effect of reaction time on regioregular poly (3-hexylthiophene-2,5-diyl) (P3HT)-wrapped hydroxylated multi-walled CNT (MWCNT-OH) nanocomposites was investigated. Five different reaction times (24, 48, 72, 96, and 120 h) were conducted at room temperature in order to clearly determine the factors that influenced the quality of wrapped MWCNT-OH. Morphological analysis using Field Emission Scanning Electron Microscopic (FESEM) and High-Resolution Transmission Electron Microscope (HRTEM) analysis showed that P3HT successfully wrapped the MWCNT-OH sidewall, evidenced by the changes in the mean diameter size of the nanocomposites. Results obtained from Raman spectroscopy, X-ray Photoelectron Spectroscopy (XPS) as well as Thermogravimetric Analysis (TGA) showed a significant effect of the wrapped polymer on the CNT sidewall as the reaction time increased. Overall, the method used during the preparation of P3HT-wrapped MWCNT-OH and the presented results significantly provided a bottom-up approach to determine the effect of different reaction times on polymer wrapping to further expand this material for novel applications, especially chemical sensors.

Tuning Molar Mass of P3HT via Direct Arylation Polycondensation Yields Optimal Interaction and High Efficiency in Nonfullerene Organic Solar Cells

Due to the simple structure and excellent scalability, regioregular poly(3-hexylthiophene) (P3HT) becomes much popular as a low-cost donor polymer partner with the emerging nonfullerene acceptors in recent years. Presently, the...

Enhancement Efficiency of Active Layer P3HT:POT:DBSA/PCBM Photoactive Solar Cell Device

In this work we have investigated thin film blend produced from regioregular poly(3-hexylthiophene) (rr-P3HT), Poly(o-toluidine) doped with dodecylbenzene sulphonic (POT:DBSA) and [6,6]-phenyl-C61 butyric acid methylester (PCBM) materials by spin coating method for application as active layer in photoactive solar cell (PSCs). A thin film uniform rr-P3HT:PCBM and rr-P3HT:POT:DBSA:PCBM were successfully deposited on the poly (3,4 ethylenedioxythiophene): poly (styrenesulfonate) (PEDOT:PSS) buffer layer substrate. The absorption spectra of the films were studied by using UV–vis spectrophotometer and Raman spectroscopy. the morphology of films is evaluated by X-ray diffraction (XRD) and atomic force microscopy (AFM) patterns. We have seen that, the efficiency enhancement for the device with a rr-P3HT:POT:DBSA:PCBM film is more significant than for the device with rr-P3HT:PCBM.

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

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.