PEDOT commercial

Many other polymeric systems are of interest in polymer LEDs. Polythiophenes have been known for some time but it was not until improved synthetic methods were developed that their potential was realised. The process involves the reaction of the substituted monomer with FeClj in chloroform solution. After polymerisation has occurred the product precipitates and is isolated and washed. Further special purification methods are required to obtain satisfactorily pure materials. One product, of commercial interest, developed by Bayer is poly(ethylenedioxy)thiophene, known as PEDOT (3.110). This product when doped with polystyrene sulfonate, sold as Baytron P, has been found to be effective as a conducting, hole-injecting layer on the ITO electrode. ... 

Fig. 9 IR spectra of commercial PDOT/PSSNa and enzymatically synthesized PEDOT/PSSNa. (Reprinted with permission from Nagarajan et al. [44]. 2008, American Chemical Society)...

The FTIR spectrum of the commercially available PEDOT/PSSNa and the enzymatically synthesized PEDOT/PSSNa were compared (Pig. 9). The spectra are scaled individually for clearer comparison. The vibrations at 1195, 1139, and 1089 cm are due to the C-O-C bond stretch in the ethylenedioxy group. The peak at 1521 cm is due to the ring stretching of the thiophene ring. The weak vibration at 1062 cm is possibly due to the C-O stretch. Peaks at 979, 937, and 840 cm are assigned to thiophene C-S bond stretching. As seen in Pig. 3, the PEDOT/PSSNa synthesized enzymatically shows similar features to those of the standard, and no major additional peaks are observed. 

Several polymer conductors are commercially available, and have been used in the demonstration of printed transistors. These include PEDOT PSS, which is a commercially available polymer conductor, as well as various versions of polyaniline. The latter is typically doped with an acid or salt to increase conductivity. Both of these material systems are water soluble and easily printable. They also typically form good interfaces to organic semiconductors, making them attractive for use in printed transistors. As with polymer dielectrics, however, it is important to note that their usability with inorganic semiconductors is questionable, of course. 

Conducting polymers like commercially available PEDOT PSS are the third class of printable conductors. However, their conductivity (maximum 500 S/ cm for PEDOT PSS [11]) is several orders of magnitude lower than the conductivity of metals. The advantages of PEDOT PSS are its transparency, flexibility and low-temperature post-processing the thermal treatment is only necessary to remove residual solvent, no sintering is required. 

PEDOT PSS represents one of the most explored conductive polymers and is available for some commercial applications in the fabrication of low-cost, flexible, and printable electronic devices. Although the PEDOTrPSS films are also widely investigated for high electrical conductivities (Liu et al., 2015), they remain obviously lower than their inorganic counterparts (Dobbelin et al., 2007). Even worse, the performances, such as efficiency and lifetime of the electronic devices are deteriorated as PSS is strongly acidic and hygroscopic. Therefore, it is critical to further improve the electrical conductivity and stability of the PEDOT PSS film. 

Tkng, P., Han, L., Zhang, L., 2014. Facile synthesis of graphite/PEDOT/Mn02 composites on commercial supercapacitor separator membranes as flexible and high-performance supercapacitor electrodes. ACS Appl. Mater. Interfaces 6,10506-10515. 

Another conducting polymer that has found commercial application is poly(3,4-ethylenedioxythiophene), PEDOT, which is marketed as a dispersion that contains poly(styrene sulfonate). This polymer dispersion is used in the manufacture of organic light-emitting diodes (OLEDs), which are materials that emit light when an electric current is applied to them (Figure 27.13). OLEDs are used for flat panel displays in televisions and cellular telephone displays. 

Copol5miers of PEDOT have the electronic and optical properties of PEDOT but can be processed from nonacidic organic solutions. Some commercial materials (TDAE) have good mechanical properties, low acidity, and wet organic substrates without the use of binders or additives. 

The reaction at room temperature results in a dark-blue, aqueous PEDOT/PSS dispersion, which is commercially available from Bayer AG under the trade name BAYTRON P and from ELECON under the trade name ELEFLEX13 2000. After dr5dng of BAYTRON P and ELEFLEX 2000, the remaining PEDOT/PSS film is highly conducting, transparent, mechanically durable, and insoluble in any common solvent. 

The electrospinning method can be applied to produce nanoflbers of PEDOT-PSS/PVAc and PEDOT/PVAc, which might be used for adhesives and coatings. For this purpose a commercially available aqueous solution of PEDOT-PSS was added in different amounts to the PVAc/A,A-dimethylformamide PMI solution, in addition to the polymerization of3,4-ethylenedioxythiophene(EDOT) by cerium(lV) ammonium nitrate (CAN) in a PVAc matrix in DMF solution as well. 

While an invaluable tool in producing conjugated polymers on conducting substrates, electropolymerization has limitations that include a lack of primary structure verification and characterization along with the inability to synthesize large quantities of processable polymer. To overcome the insolubility of PEDOT, a water-soluble polyelectrolyte, poly(styrenesulfonate) (PSS) was incorporated as the counterion in the doped PEDOT to yield the commercially available PEDOT/PSS (Baytron P) (39), which forms a dispersion in aqueous solutions [140]. While this polymer finds most of its application as a conductor for antistatic films, solid state capacitors, and organic electronic devices, its electrochromism is distinct and should not be ignored. 

XPS of S(2p) and 0(ls) Core Levels of a Commercial PEDOT-PSS Blend Valence Band UPS Electropolymerized vs. Chemically Prepared Systems Surface Composition Revisited. Photon Energy Dependent XPS Synopsis.21-29... 

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