PEDOT critical

Figure 5.13 (top) displays the frequency spectra of the measured capacitance for temperatures ranging from 20 K to 300 K for a standard cell (ITO/PEDOT/MDMO-PPV PCBM/Al). The arrow indicates increasing temperatures. One clearly observes a step which is shifted to higher frequencies as the temperature increases. In order to evaluate the position of the steps, it is better to plot wdC/dw versus w, rather than C(u>) versus w. Figure 5.13 (bottom) shows the normalised deviated frequency spectrum of the capacitance. The steps now appear as maxima within the individual curves, and the corresponding critical frequency wq can be derived more ac-... 

Unity [39] or due to interface interactions [14]. It must be pointed out here that a critical thickness is found for electrodes made of aluminium, not for PEDOT PSS [14], Our data are consistent in this context. In Section 21.3.3 we already showed reactive interactions between P(VDF-TrFE) and aluminium, not for the P(VDF-TrFE)/PEDOT PSS interface. This becomes even more important when the thickness of P(VDF-TrFE) film is further downscaled. 

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. 

As a critical component of the DSSC, counter electrode is also a key to the flexibility of the device. Some flexible conductive materials, such as conducting polymers, carbon-based nanomaterials and their composites have been employed as flexible counter electrodes to replace the Pt electrode in the fabrication of flexible DSSCs. For instance, after coating with conducting polymer PEDOT, a flexible counter electrode was developed with low sheet resistance and served as an ideal candidate in replacement of the conventional Pt counter electrode (Fig. 9.1B) (Mozer et al., 2010). 

A control series of films, prepared by mixing the PS latex and PEDOT PSS, was investigated to determine the critical PEDOT PSS loading required to prepare a conductive film without the presence of CNTs. An insulator-conductor transition around 2.2 wt% is observed for PS/PEDOT PSS blends. 

In neural stimulation, conducting polymers are usually electrochemically deposited on metal seed layers such as Pt and Au. For such noncovalently coated polymer layers, the adhesion to metal is critical for the stability of long-term applications. In a recent study, the chronic behavior of PEDOT-coated electrodes was examined [33]. Thirty electrodes from three electrode arrays were stimulated and evaluated for stability. It was found that the well-coated PEDOT electrodes were... 

The continuous improvement of PEDOTrPSS, or poly(3,4-ethylenedioxythio-phene) poly(styrenesulfonate), pol5uner dispersions over the last decade has made the application of these dispersions for polymer capacitors feasible. Waterborne PEDOT PSS dispersions were developed for the formation of the outer polymer layer first. The requirement on conductivity is much lower for this application than for the inner solid electrolyte because the electrical current passes perpendicular to the 5 to 50 microns thick outer polymer layer. Filmforming properties, adhesion to the anode body and edge, and comer coverage, which are critical to guarantee good barrier layer properties, are adjusted by appropriate formulations of PEDOTPSS. In Figure 10.10 a dense outer layer made of a PEDOTPSS dispersion on a tantalum capacitor is shown. 

In the presence of acid the manganese dioxide reduces to soluble manganese(II) and simultaneously polymerizes the monomer EDOT to the conductive polymer PEDOT. The acid anions serve as charge-balancing counterions and get incorporated into the polymer. The chemical nature of the acid employed will influence the nucleation and the crystallization of the polymer. Morphology and achievable conductivity of the resulting polymer will therefore be critically influenced by the acid involved. ... 

A commerdally available PEDOT associated with poly(styr-enesuffonate) (PSS) counterion, Baytron P was studied before and after annealing at 150 °C. Baytron P consists of PEDOT chemically polymerized by using the oxidant FeCls and residual amounts of FeCls are often found in HREM images. "The semicrystalfine PEDOT itself is much more beam sensitive, and more poorly ordered than the inorganic FeCls. The critical dose of the PEDOT has been determined to be around 0.1 Ccm . ... 

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