Copolymers Based on 1,3-Bis(carbazol-9-yl)benzene and Three 3,4-Ethylenedioxythiophene Derivatives as Potential Anodically Coloring Copolymers in High-Contrast Electrochromic Devices

Abstract

Abstract:In this study, copolymers based on 1,3-bis(carbazol-9-yl)benzene (BCz) and three 3,4-ethylenedioxythiophene derivatives (3,4-ethylenedioxythiophene (EDOT), 3,4-(2,2-dimethylpropylenedioxy) thiophene (ProDOT-Me 2 ), and 3,4-ethylenedithiathiophene (EDTT)) were electrochemically synthesized and their electrochemical and electrochromic properties were characterized. The anodic copolymer P(BCz-co-ProDOT) with BCz/ProDOT-Me 2 = 1/1 feed molar ratio showed high optical contrast (∆T%) and coloring efficiency (η), measured as 52.5% and 153.5 cm 2 ·C −1 at 748 nm, respectively. Electrochromic devices (ECDs) based on P(BCz-co-EDOT), P(BCz-co-ProDOT), and P(BCz-co-EDTT) as anodic polymer layers, and poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid) (PEDOT-PSS) as cathodic polymer layer were fabricated. P(BCz-co-ProDOT)/triple-layer PEDOT-PSS ECD showed three different colors (light yellow, yellowish-blue, and dark blue) at different applied potentials. In addition, the highest optical contrast (∆T%) of P(BCz-co-ProDOT)/triple-layer PEDOT-PSS ECD was found to be 41% at 642 nm and the coloration efficiency was calculated to be 416.5 cm 2 ·C −1 at 642 nm. All ECDs showed satisfactory optical memories and electrochemical cyclic stability.

Electrosynthesis of Copolymers Based on 1,3,5-Tris(N-Carbazolyl)Benzene and 2,2′-Bithiophene and Their Applications in Electrochromic Devices

“…The τb and τc values of the PtnCz/PProDOT-Me2, P(tnCz1-bTp1)/PProDOT-Me2, P(tnCz1-bTp2)/PProDOT-Me2, P(tnCz1-bTp4)/ PProDOT-Me2, and PbTp/PProDOT-Me2 ECDs were smaller than those of the PtnCz, P(tnCz1-bTp1), P(tnCz1-bTp2), P(tnCz1-bTp4), and PbTp films, respectively, in 0.2 M LiClO4/(ACN + DCM) solution, implying that the ECDs changed color faster from the bleached to the colored states and from the colored to the bleached states than did the PtnCz, P(tnCz1-bTp1), P(tnCz1-bTp2), P(tnCz1-bTp4), and PbTp films in 0.2 M LiClO4/(ACN + DCM) solution. The comparisons of ΔTmax and η for the reported ECDs are summarized in Table 6; the P(tnCz1-bTp2)/PProDOT-Me2 ECD showed a higher ΔTmax than that reported for the PdNCz/PEDOT [36], PbmCz/PEDOT [37], PHCz/PEDOT [38], P(dNCz-Hcp)/PEDOT [39], P(dNCz-bT)/PEDOT [40], and P(Cz4-6CIn1)/PProDOT-Me2 ECDs [41], and the ΔTmax value of the P(tnCz1-bTp2)/PProDOT-Me2 ECD as comparable to that of the P(BCz-ProDOTme)/PEDOT-PSS ECD [42]. In addition, the ΔT value of the P(tnCz1-bTp2) ECD was lower than that reported for a non-mechanical microiris based on viologen and phenazine complementary electrochromic materials [43].…”

“…P(dNCz-bT)/PEDOT [40], P(Cz4-6CIn1)/PProDOT-Me2 [41], and P(BCz-ProDOTme)/PEDOT-PSS ECDs [42]. The high ΔTmax and η values of the P(tnCz1-bTp2)/PProDOT-Me2 ECD makes P(tnCz1-bTp2) a potential electrochromic material for ECD applications.…”

Dithienylpyrrole- and Tris[4-(2-thienyl)phenyl]amine-Containing Copolymers as Promising Anodic Layers in High-Contrast Electrochromic Devices

“…As displayed in Figure 5, the absorption peaks of P(MPS-co-TTPA), P(MPO-co-TTPA), and P(ANIL-co-TTPA) films were found at 417, 369, and 385 nm, respectively, in their neutral state, which indicated the π-π* transition of P(MPS-co-TTPA), P(MPO-co-TTPA), and P(ANIL-co-TTPA) in [EPI + ][TFSI -] solution. Upon applying potentials more than 1.2 V, the peaks of P(MPS-co-TTPA), P(MPO-co-TTPA), and P(ANIL-co-TTPA) films at 417, 369, and 385 nm, respectively, decreased little by little and their charge carrier absorption bands appeared at 964, 914, and 960 nm, respectively, implying the formation of polaron and bipolaron of copolymer films [26]. The band gap energy values (E g ) of PMPS, PMPO, PANIL, PTTPA, P(MPS-co-TTPA), P(MPO-co-TTPA), and P(ANIL-co-TTPA) can be calculated according to the following Planck equation [27,28],…”

Applications of Poly(indole-6-carboxylic acid-co-2,2′-bithiophene) Films in High-Contrast Electrochromic Devices

“…In addition, the τ c of P(Inc-co-bT)/PEDOT-PSS ECD is shorter than those reported for PInc/PProDOT-Et 2 [29], PIn/PEDOT [30], and P(Cz-co-CIn)/PProDOT-Me 2 [31] ECDs, which makes P(Inc-co-bT)/PEDOT-PSS ECD desirable for electrochromic applications. The optical memory effect is a crucial character for ECDs [32]. The optical memory of PInc/PMMA-PC-ACN-LiClO4/PEDOT-PSS, P(Inc-co-bT)/PMMA-PC-ACN-LiClO4/PEDOT-PSS, and PbT/PMMA-PC-ACN-LiClO4/PEDOT-PSS ECDs was evaluated by giving potential for 1 s for each 100 s time interval.…”