Broadly Absorbing Electrochromic Polymers

20170267811 · 2017-09-21

    Inventors

    Cpc classification

    International classification

    Abstract

    Copolymers including dioxythiophene repeating units and no acceptor units allow the formation of electrochromic polymers (ECPs) with vivid neutral state colors and very colorless oxidized states that can be switched rapidly. The dioxythiophene repeating units can included in sequences where all of one type of dioxythiophene is included exclusively as isolated dyads or triads within the copolymer, or the copolymer can be an alternating copolymer with propylenedioxythiophene units. Other non-acceptor units can be included in the copolymers. The copolymers are rendered organic solvent soluble by alkyl substituents on repeating units. The inclusion of sterically encumbered acyclic dioxythiophene (AcDOT) units promotes red color while unsubstituted ethylenedioxythiophene (EDOT) units promote blue colors, and their respective content can be manipulated to achieve a desired neutral state color. Soluble copolymers comprising at least 50% EDOT repeating units can be used in supercapacitor applications.

    Claims

    1. An acceptor free dioxythiophene comprising electrochromic polymer (ECP), comprising: at least one copolymer block having a multiplicity of repeating units, wherein the copolymer consists of repeating units with at least one dioxythiophene repeating unit residing exclusively as isolated dyads, triads, or both within the copolymer, the copolymer is an alternating copolymer of a repeating unit comprising a propylenedioxythiophene (ProDOT) and a repeating unit comprising an acyclic dioxythiophene (AcDOT), a phenylene dioxythiophene (PheDOT) or an ethylene dioxythiophene (EDOT), or the copolymer is an alternating copolymer of a repeating unit comprising an acyclic dioxythiophene (AcDOT) and a repeating unit comprising a phenylene dioxythiophene (PheDOT); optionally, further consisting of at least one non-dioxythiophene repeating unit selected from arylenes, thiophenes, furans, pyrroles, selenothiophenes, N-substituted pyrroles, acyclic dioxyfurans, acyclic dioxypyrroles, propylenedioxyfurans, propylenedioxypyrroles, N-substituted propylenedioxypyrroles, phenylene dioxypyrroles, N-substituted phenylene dioxypyrroles, ethylenedioxyfurans, acyclic dioxyselenophenes, ethylenedioxyselenophenes, phenylene dioxyselenophenes, propylenedioxyselenophenes, ethylenedioxpyrroles, and N-substituted ethylenedioxpyrroles placed either regularly or randomly within the dioxythiophene repeating units other than within the isolated dyads; wherein at least one of the dioxythiophene repeating units has an alkyl comprising substituent and is present in at least five percent to provide solubility of the electrochromic polymer in an organic solvent; and wherein no acceptor repeating units are included in the copolymer block.

    2. The acceptor free dioxythiophene comprising electrochromic polymer (ECP) according to claim 1, wherein the dioxythiophene repeating unit residing exclusively as isolated dyads or triads are ethylenedioxythiophene (EDOT.sub.2) or (EDOT.sub.3).

    3. The acceptor free dioxythiophene comprising electrochromic polymer (ECP) according to claim 2, wherein the ethylenedioxythiophene (EDOT.sub.2) or (EDOT.sub.3) is unsubstituted.

    4. The acceptor free dioxythiophene comprising electrochromic polymer (ECP) according to claim 1, wherein the dioxythiophene repeating unit residing exclusively as isolated dyads is propylenedioxythiophene (ProDOT.sub.2).

    5. The acceptor free dioxythiophene comprising electrochromic polymer (ECP) according to claim 1, wherein the dioxythiophene repeating unit residing exclusively as isolated dyads is substituted dioxythiophene (AcDOT.sub.2).

    6. The acceptor free dioxythiophene comprising electrochromic polymer (ECP) according to claim 1, wherein the copolymer is: AcDOT.sub.2-EDOT.sub.2; AcDOT-ProDOT; AcDOT.sub.2-ProDOT; AcDOT.sub.2-EDOT.sub.2; ProDOT.sub.2-EDOT; ProDOT-EDOT; or ProDOT.sub.2-EDOT.sub.2.

    7. The acceptor free dioxythiophene comprising electrochromic polymer (ECP) according to claim 1, wherein the copolymer is: AcDOT-EDOT.sub.3; ProDOT-EDOT.sub.3; AcDOT.sub.2-EDOT.sub.3; or ProDOT.sub.2-EDOT.sub.3.

    8. The acceptor free dioxythiophene comprising electrochromic polymer (ECP) according to claim 1, wherein the alkyl substituent is a C.sub.3 to C.sub.20 alkyl.

    9. An electrochromic device, comprising at least one acceptor free dioxythiophene comprising electrochromic polymer (ECP) according to claim 1.

    10. A supercapacitor, comprising an acceptor free dioxythiophene comprising electrochromic polymer (ECP) according to claim 3, wherein the ECP is a single block, and wherein EDOT or PheDOT repeating units are at least 50% of all repeating units of the ECP.

    Description

    BRIEF DESCRIPTION OF DRAWINGS

    [0011] FIG. 1 shows the structure of electrochromic polymers (ECPs) according to an embodiment of the invention.

    [0012] FIG. 2 shows absorbance spectra of selected electrochromic polymers (ECPs) according to an embodiment of the invention, a prior art alternating copolymer and prior art homopolymers for comparison.

    [0013] FIG. 3a and FIG. 3b show transmittance spectra over the range of potentials that converts the neutral state colored copolymer to an oxidized state transmissive copolymer for films sprayed to an optical density of about 1.2 a.u. of ProDOT.sub.2-EDOT.sub.2 and AcDOT.sub.2-ProDOT, respectively, for potential steps of 50 mV with 0.5 M TBAPF.sub.6 in PC with a Pt wire as counter electrode and an Ag/Ag.sup.+ reference electrode calibrated to Fc/Fc.sup.+ with a value of 82 mV, according to an embodiment of the invention.

    [0014] FIG. 4 shows colorimetry plots for blue and magenta hue ECPs, according to embodiments of the invention, where all films sprayed to about 1.0 a. u. , where the direction of the arrow indicates increasing planarity of repeating units of the n-conjugated backbone (relaxation), left and above, and increased orthogonality of repeating units of the π-conjugated backbone (strain), right and below.

    [0015] FIG. 5a shows a plot of % transmittance over the visible spectrum for ECPs according to an embodiment of the invention, and a prior art AcDOT-EDOT copolymer in the fully oxidized state, and FIG. 5b shows a plot of the lightness values (L*) for all ECPs as a function of voltage for films sprayed to about 1.0 a. u.

    [0016] FIG. 6 shows the structure, color values, % transmittance and colorimetry plots for ProDOT.sub.2-EDOT.sub.2, according to an embodiment of the invention, which is free of an acceptor repeating unit and the inferior color intensity and transmissive oxidized state of a similarly colored ProDOT-BTD alternating copolymer having an acceptor repeating unit.

    [0017] FIG. 7 shows the absorbance spectra for ECPs, according to an embodiment of the invention, with included phenylene repeating units with a prior art ProDOT-phenylene alternating copolymer EPC-Yellow-1 and the alternation copolymer ProDOT-EDOT (ECP-Periwinkle-1) according to an embodiment of the invention.

    [0018] FIG. 8 shows reaction schemes for the direct arylation method for synthesizing ECPs, according to an embodiment of the invention, that have random placements with isolated dioxythiophene dyads within the copolymer (terpolymer).

    [0019] FIG. 9 shows current density plots over the potential range for switching of ECPS according to an embodiment of the invention, where EDOT dyads provide high fill factors for soluble copolymers that can be used in supercapacitors.

    [0020] FIG. 10a and FIG. 10b show voltage window plots for ProDOT-EDOT.sub.2 and ProDOT.sub.2-EDOT.sub.2, respectively, according to an embodiment of the invention, with plots of their fill factors over the window for devices employing these copolymers for supercapacitance applications.

    [0021] FIG. 11a shows current density plots over the potential range for ProDOT-EDOT.sub.2, according to an embodiment of the invention, of different capacitance and thickness prepared by a solution deposition and FIG. 11b shows its comparison to a similarly thick PEDOT homopolymers supercapacitor prepared by electropolymerization.

    DETAILED DISCLOSURE

    [0022] Embodiments of the invention are directed to electrochromic polymers (ECPs) that are copolymers that contain only electron donor repeating units and, optionally, aryl repeating units, where at least one of the repeating units is 3,4-dioxythiophenes that displays a variety of colors, including, but not limited to, black, brown, deep purple, magenta, pink, blue and cyan in the reduced states. No electron acceptor repeating units are within the polymer backbone. The ECPs have 3,4-dioxythiophene repeating units that alternate or are randomly situated within a polymer backbone with other 3,4-substituted thiophene repeating units and, optionally, other aryl ring repeating units, fused ring repeating units, or other donor heterocycle repeating units, including pyrroles and furans. These all-donor polymers exhibit a high electrochromic contrast, switching from a vibrant colored state to a highly transmissive state. Copolymers, according to an embodiment of the invention, have at least one dioxythiophene repeating unit that resides exclusively within the backbone as isolated dyads, triads, or both dyads and triads, or the copolymer is an alternating copolymer of a repeating unit that are propylenedioxythiophene (ProDOT) and an acyclic dioxythiophene (AcDOT), a phenylene dioxythiophene (PheDOT) or an ethylene dioxythiophene (EDOT). For example the copolymer can be ProDOT-alt-AcDOT, ProDOT-alt-EDOT, or ProDOT-PheDOT. The copolymer can be AcDOT-alt-PheDOT. FIG. 1 shows some exemplary ECPs including prior art homopolymers and copolymers according to embodiments of the invention, where the alkyloxy substituent on the AcDOT and ProDOT are 2-ethylhexanoxy groups. Additionally, an exemplary ProDOT-EDOT.sub.2 displays Mn=55 kDa, PDI=1.80, Yield=92%, Absorbance Onset=1.71 eV, and λ.sub.max=613 nm.

    TABLE-US-00001 TABLE 1 All polymer molecular weight, yield, and solid state spectroscopy data. Molecular Weight (Mn, PDI, solvent Yield Absorption λ.sub.max Polymer (kDa)). (%) Onset (eV) (nm) ProDOT 12.3, 1.77, THF 40 1.97 555, 606 ProDOT.sub.2-EDOT NA 82 1.81 590 ProDOT-EDOT NA 24 1.75 597 ProDOT.sub.2-EDOT.sub.2 NA 70 1.74 606 AcDOT 279.7, 2.08, THF 62 2.10 490 AcDOT.sub.2-ProDOT 176.0, 2.20, THF 82 2.01 536, 579 AcDOT-ProDOT 51.8, 2.37, THF 97 2.00 541, 587 AcDOT-EDOT 30.9, 1.21, THF 75 1.84 553 AcDOT.sub.2-EDOT.sub.2 NA 60 1.81 557

    [0023] FIG. 2 shows visible spectra for the copolymers, according to embodiments of the invention (and prior art ProDOT, and AcDOT) that represent two groups, one group with blue hues consisting of ProDOT-EDOT, ProDOT.sub.2-EDOT, and ProDOT.sub.2-EDOT.sub.2 and a second group with magenta hues consisting of AcDOT-ProDOT, AcDOT.sub.2-ProDOT, and AcDOT-EDOT. Additionally AcDOT.sub.2-EDOT.sub.2, which has a purple hue, is included. These groups of blue and magenta ECPs display effects of subtle “relaxation” and torsional “strain” within the copolymer backbone on the copolymers' spectra.

    [0024] The copolymers, according to an embodiment of the invention, undergo a “break in” where the copolymer films are electrochemically conditioned upon 25 cycles via cyclic voltammetry (CV) where the current stabilizes leading to reproducible identical cycles thereafter. In a typical “break in” the first and second cycle shows a significant current decrease, after which the current decreases slightly between successive cycles until no discernable difference is observable by the 25.sup.th cycle. All of the copolymers and the ProDOT homopolymer oxidize easily where the onsets for the oxidation potentials range from −490 to 206 mV. The AcDOT (ECP-Orange) homopolymers display an oxidation potential of 260 mV, which is consistent with its pendant groups' bulkiness. The “break in” is consistent with a steric relaxation along the conjugated backbone where the conformation between adjacent repeating units allows greater average conjugation lengths. Particularly where the repeating unit is EDOT and is adjacent to repeating units with large solubilizing substituents, drastic changes between the pristine and broken-in film states can occur. Greater steric strain is introduced by AcDOT repeating units, and greater AcDOT content permits minimal change between the pristine and “broken in” states. Differential pulse voltammetry indicates that by increasing steric strain of the copolymer, the oxidation potential onset is raised relative to copolymers, while repeating units that permit relaxation to longer average conjugation lengths lower the onset.

    [0025] In concert with the changes observed in CV behavior during “break in”, the copolymer film's spectra redshifts and an increase in optical density is induced upon “relaxation” to greater conjugation lengths, while such changes in the spectra are reduced with increasing content of repeating units that induce steric hindrance to planarity between repeating units. For example, for the copolymer AcDOT.sub.2-ProDOT, there is no spectral difference between the pristine and “broken in” state, which can be correlated to a minimal change during CV. As indicated in FIG. 2a, as the copolymer's EDOT content increases, one observes an increased long wavelength absorption relative to the ProDOT and AcDOT homopolymers. The copolymers possess considerably lower band gaps relative to ProDOT, and due to greater absorption of long wavelength light, the copolymer films appear periwinkle-blue to the eye. The red-shifted absorption onset of around 700-750 nm allow these polymers to be used as organic soluble analogues of PEDOT. Conversely, as indicated in FIG. 2b, increasing the steric hindering AcDOT repeating unit content, shorter wavelength absorption is induced relative to ProDOT. As these copolymers absorb more of the high energy portion of the visible spectrum, the amount of blue light reflected decreases to render these copolymer films “reddened” and result in rather vivid magenta and pink neutral state colors.

    [0026] The comonomers' composition has an overall effect on vibronic coupling observed in the spectra. Relative to the ProDOT homopolymer, which exhibits a high degree of order, characterized by multiple defined maxima in the spectrum, inclusion of more sterically bulky AcDOT repeating units, as indicated by the spectra of AcDOT-ProDOT and AcDOT.sub.2-ProDOT, promotes little decrease in the degree of vibronic coupling, evidenced by little decrease in the definition of the multiple peaks. In contrast, by increasing the EDOT repeating unit content, there is a decrease in the degree of vibronic coupling observed as the low steric hindrance imposed by the EDOT units, which allows the propylene bridge on neighboring ProDOT repeating units to experience greater conformational freedom and disorder to the polymer backbone, reducing the degree of vibronic coupling and broadening the spectra relative to that of the ProDOT homopolymer.

    [0027] These conformational effects extend to the spectroelectrochemistry of the copolymers according to embodiments of the invention. Transmittance spectra over a range of potentials for two exemplary copolymers, according to an embodiment of the invention, ProDOT.sub.2-EDOT.sub.2 and AcDOT.sub.2-ProDOT, are shown in FIG. 3. The copolymers have two propylenedioxythiophene repeating units, a dyad, alternating with two ethylenedioxythiophene repeating units, a second dyad, (ProDOT.sub.2-EDOT.sub.2) and two acyclic dioxythiophene repeating units, a dyad, alternating with one propylenedioxythiophene repeating units (AcDOT.sub.2-ProDOT). As is seen in FIG. 3 for these two exemplary copolymers, all copolymers, according to embodiments of the invention, exhibit changes in contrast of more than 60% at λ.sub.max, as is presented in Table 2, below. ProDOT.sub.2-EDOT.sub.2 and AcDOT.sub.2-ProDOT exhibit the highest contrast values, 75 and 73 Δ % T at λ.sub.max, respectively, because of the least residual visible absorption in the fully oxidized transmissive state, even for thicker films. The copolymers with EDOT repeating units have a broadened potential range over which the copolymer switches with subtle changes over the duration of oxidation, as illustrated in FIG. 3a, while copolymers incorporating AcDOT repeating units display a narrowed potential window with gross changes over each potential step. This difference in behavior can be attributed to delocalized conformational defects due to the greater orthogonality of adjacent repeating units (less planarity) induced by the steric hindrance to planarity imposed by the AcDOT repeating units of the AcDOT-ProDOT and AcDOT.sub.2-ProDOT copolymers, there is significant resistance to planarization on initial oxidation, but upon increasing oxidation potential, localized planarization promotes rapid propagation of planarization between neighboring repeat units.

    TABLE-US-00002 TABLE 2 L*a*b* color coordinates for all polymers in the neutral and transmissive oxidized states and total change in contrast upon switching between the extremes Δ% T Neutral State Oxidized State Δ% T Neutral State Oxidized State Strained Polymers (at λ.sub.max) L*, a*, b* L*, a*, b* Strained Polymers (at λ.sub.max) L*, a*, b* L*, a*, b* AcDOT 48 72, 42, 53 81, −2, −7 AcDOT.sub.2-EDOT.sub.2 70 38, 38, −44 91, −2, −4 ProDOT 71 50, 51, −37 88, −1, −2 AcDOT-EDOT 63 49, 41, −35 88, −3, −4 AcDOT.sub.2-EDOT.sub.2 70 38, 38, −44 91, −2, −4 ProDOT 71 50, 51, −37 88, −1, −2 ProDOT.sub.2-EDOT 71 33, 32, −63 90, −2, −3 AcDOT-ProDOT 72 47, 70, −36 91, −2, −3 ProDOT-EDOT 68 40, 16, −43 85, −4, −5 AcDOT.sub.2-ProDOT 73 56, 59, −16 91, −2, −1 ProDOT.sub.2-EDOT.sub.2 75 37, 12, −63 92, −3, −3 AcDOT 48 72, 42, 53 81, −2, −7

    [0028] The switching kinetics for all copolymers, according to embodiments of the invention, which can be probed by chronoabsorptometry, is rapid from their full neutral color to their oxidized transmissive state, where repeated switching in 1 second intervals show minimal loss in contrast. Contrast loss observed at ½ and ¼ second cycles is consistent with diffusion limiting processes of electrolyte migration within the copolymer film, as after cycling at high switching speeds; the copolymers are all capable of regaining high levels of contrast with no apparent negative effects such as delaminating, or blistering.

    [0029] The colorimetric properties of each polymer, as a*b* color tracks, are presented in FIG. 4, which includes photographs of the polymer films in the neutral and oxidized state, with the color values of each polymer in the neutral and fully oxidized states given in Table 2, above. The color trend for the blue hued ECPs with increasing “relaxation,” from high degrees of orthogonality between repeating units to high degrees of conjugation of π-bonds between repeating units, is a progression from orange through purple to blue a*b* values as follows: AcDOT (42, 53).fwdarw.ProDOT (51, −37).fwdarw.AcDOT.sub.2-EDOT.sub.2 (38, −44).fwdarw.ProDOT.sub.2-EDOT (32, −63).fwdarw.ProDOT-EDOT (16, −43) ProDOT.sub.2-EDOT.sub.2 (12, −63).fwdarw.ProDOT-EDOT.sub.2 (10, −56). The long wavelength absorption transitions, induced through relaxation, occur with increased EDOT unit content of the copolymers, with color values in the neutral state progressing to lower a* values, indicating less purple and more blue hue due to the progressive transmission of more blue and less red light. The absorption of the copolymer ProDOT-EDOT.sub.2 closely matches that of PEDOT, with L*, a*, b* values of 35, 10, −54. The color trend for the magenta hued ECPs with increasing steric strain, which induces orthogonality at the cost of conjugation length, is a progression from purple through pink to orange a*b* values as follows: AcDOT.sub.2-EDOT.sub.2 (38, −44).fwdarw.AcDOT-EDOT (41, −35).fwdarw.ProDOT (51, −37).fwdarw.AcDOT-ProDOT (70, −36).fwdarw.AcDOT.sub.2-ProDOT (59, −16).fwdarw.AcDOT (42, 53). This increased steric strain coincides with the increase of the AcDOT content with a progression to higher b* values indicating less purple and more red hue due to the progressive transmission of more red and less blue light. The AcDOT.sub.2-ProDOT copolymer nearly matches the standard magenta of L*, a*, b* of 52, 50, −15 after “break in” and is capable of providing more accurate color mixing in the cyan-magenta-yellow (CMY) subtractive regime using soluble polymers.

    [0030] The minimal hue and saturation of color in the oxidized form for all of these copolymers arises from minimal residual absorption in the visible spectrum because of their electron rich, all-donating character, as shown by FIG. 5a. The lightness values (L*) are a function of voltage during switching of the copolymers, as shown in FIG. 5b. Upon oxidation all lightness values are high, 85 or greater.

    [0031] Through incorporation of EDOT repeating units, a subtle tuning of the all donor copolymers can yield materials with low band gaps, such as the (ProDOT.sub.2-EDOT.sub.2).sub.n copolymer, where the blue neutral states have color values that are comparable to those of blue-to-transmissive ECP designed with donor-acceptor (D-A) units. A comparison between the neutral states for the ProDOT.sub.2-EDOT.sub.2 copolymer, according to an embodiment of the invention, and ECP-Blue, a ProDOT-BTD alternating copolymer, where BTD is benzothiadiazole, is illustrated in FIG. 6. FIG. 6a gives the transmittance spectra of ECP-Blue, which displays dual band absorptions where the shorter wavelength absorption is for a π to π transition and the longer wavelength absorption is due to the donor-acceptor charge transfer interactions. The ProDOT.sub.2-EDOT.sub.2 displays an absorption that was attained with an onset at shorter wavelengths (1.74 eV), remaining at the edge of the visible spectrum. Through the D-A approach, a lower onset was achieved (1.53 eV) with a window of transmission at 431 nm between the two bands. The ProDOT.sub.2-EDOT.sub.2 copolymer allows a majority of blue light, and a minimal amount of red light, to be transmitted and a saturated blue color is observed. The ECP-Blue has a more redshifted onset from the CT absorption, which allows more green than red light to transmit, however, the higher energy π to π* absorbs more blue and violet light and results in a less saturated sky-blue color. Though they have similar numerical color values, ProDOT.sub.2-EDOT.sub.2 appears more saturated because more blue light is transmitted.

    [0032] The electron rich character of all the donor polymers allows full bleaching, being oxidized to where a*b* color values approach zero and L* is high at potentials that are lower than those exhibited by ECP-Blue. In the oxidized transmissive states the 7c-electron donating character of the oxygens residing on the β-positions of thiophene of the all donor copolymer (ProDOT.sub.2-EDOT.sub.2) imparts stabilization to the oxidized form, red-shifting the overall absorption with a diminished absorption between 700 and 1,000 nm relative to the donor-acceptor system (ECP-Blue). In FIG. 6a one can see a significant absorption tailing into the long wavelength portion of the visible (600-720 nm) with a peak in the NIR at ˜1460 nm for ECP-Blue's transmissive state with a blue tint upon oxidation, as can be seen in FIG. 6c, while ProDOT.sub.2-EDOT.sub.2 exhibits minimal tailing in the same portion and is nearly colorless in the oxidized state. Hence, while lower gaps can be attained by donor-acceptor copolymers, the lower gap is attained with a decrease in the electrochromic contrast relative to an all donor copolymer because of the tailing absorption of incorporated electron deficient acceptors. Hence, it was discovered that by employing copolymers free of acceptor repeating units, particularly where repeating units with minimal steric requirements are included, copolymers with comparably low gaps are available that can be employed for color applications with high electrochromic contrast gaps using known dioxythiophene repeating units.

    [0033] The copolymers, according to embodiments of the invention, can be prepared by any method, including: Grignard metathesis (GRIM); Stille coupling; Suzuki coupling; or oxidative polymerization (O×P). A direct arylation copolymer synthesis, using the method disclosed in International Patent Application Publication No. WO/2014/205024, entitled “Method for Preparing Dioxyheterocycle-Based Electrochromic Polymers,” and incorporated herein by reference, was employed for the exemplary polymers disclosed herein. Advantageously, this method affords resulting polymers that display a narrower molecular weight distribution than does the equivalent polymer prepared at lower temperatures and distributions that are equivalent or lower than the equivalent polymer prepared by the alternative synthetic routes, above. The direct arylation method provides a quality copolymer with few impurities, particularly metallic impurities, and with few purification steps. The copolymerization of a ProDOT and EDOT to form the alternation copolymer (ProDOT-EDOT), also called ECP-Periwinkle-1, is shown below:

    ##STR00001##

    [0034] Direct arylation can be employed for the formation of random copolymers, where the monomers ProDOT, EDOT, and phenylene with various monomer feed ratios can be used to prepare terpolymers. According to an embodiment of the invention, the terpolymers can be those that do not have any dyads of the same repeating unit. By varying the feed ratios of phenylene to EDOT, one can attain drastically varying colors for copolymers and terpolymers, as shown below, which can switch to various colored states as indicated in FIG. 7, where ECP-yellow, the alternating copolymer of ProDOT and phenylene, is included.

    ##STR00002##

    [0035] In an embodiment of the invention, a regular or random copolymer can be prepared where a repeating unit is within the copolymer as dyads of the copolymer and are never present as the single repeating unit. This is illustrated in FIG. 8 where three copolymers are terpolymers having: one repeating unit of the three that is present only as dyads with the other two repeating units being present only as isolated monads; two repeating units of the three that are present only as dyads with the other repeating unit being present as isolated monads; and all three repeating units present only as dyads. As illustrated for the polymerization of dimeric oligomers that function as monomers with respect to the polymerization process of ProDOT.sub.2, EDOT.sub.2, or thiophene.sub.2 in FIG. 8, the dimeric oligomers that function as a monomer toward the polymerization process can be AcDOT.sub.2 or other non-acceptor dimers that lead to isolated dyads of the resulting copolymer.

    [0036] In an embodiment of the invention, the copolymers comprise at least 50% EDOT or PheDOT repeating units and up to 50% ProDOT, where the copolymer has EDOT.sub.2 as dyads and is soluble in at least one organic solvent. These materials have a high fill factor (FF), in excess of 80%, as shown in FIG. 9, and permit the fabrication of devices that can be charged/discharged in >1.0 V window up to a 1.6 V widow without compromising the fill factor, as shown in FIG. 10, and have switching speeds of less than one second. The switching speed for an exemplary ProDOT.sub.2-EDOT.sub.2 is 0.53 seconds where the specific capacitance is 5.6±0.35 mF/cm.sup.2 and a capacitance of 31.5±2.0 F/g was observed and a switching speed of 0.51 seconds for an exemplary ProDOT-EDOT.sub.2 with a specific capacitance of 6.5±0.35 mF/cm.sup.2 and capacitance of 36.1±3.9 F/g. As shown in FIG. 11, the solution deposited ProDOT-EDOT.sub.2 copolymer displays a fill factor as a supercapacitor that is nearly identical to that of EDOT homopolymers deposited by electrochemical polymerization.

    [0037] All patents, patent applications, provisional applications, and publications referred to or cited herein are incorporated by reference in their entirety, including all figures and tables, to the extent they are not inconsistent with the explicit teachings of this specification.

    [0038] It should be understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application.