Studies on copolymers based on dicarbazole derivatives and thiophene derivatives in electrochromic devices

• Main Authors: SUN, PEI-JUN, 孫培鈞
• Other Authors: KUO, CHUNG-WEN
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/bxuzcb

碩士 === 國立高雄科技大學 === 化學工程與材料工程系 === 107 === Copolymers based on 5-[3,5-di(carbazol-9-yl)phenyl]benzene-1,3-dicarbonitrile (dCzCN) and four bithiophene derivatives (2,2'-bithiophene (bTP), 2-(2-thienyl)furan (TF), 4H-cyclopenta[2,1-b:3,4b’]dithiophene (CPDT), and cyclopentadithiopheneketone (CPDTK)) are electrochemically synthesized on ITO electrodes. The spectroelectrochemical properties of four copolymer films are investigated by UV-Vis spectra and cyclic voltammetry (CV). Spectroelectrochemical studies indicated that P(dCzCN-co-bTP) film is brown, green, and blue in the neutral, oxidation, and highly oxidized state, respectively. P(dCzCN-co-bTP) anodic copolymer shows high optical contrast (ΔT%), and it is measured as 39.5% at 680 nm. ECDs are fabricated using P(dCzCN-co-bTP), P(dCzCN-co-TF), P(dCzCN-co-CPDT), and P(dCzCN-co-CPDTK) as anodic polymer layers, and poly(3,4-ethylenedioxythiophene) (PEDOT) as complementary electrodes, and hybrid polymer electrolytes as gel electrolytes. The P(dCzCN-co-bTP)/PEDOT device exhibits stable electrochromic performance, with good optical contrast of 38% at 630 nm, and achieves a high coloring efficiency of 531 cm2 C-1 at 630 nm. Homopolymer (poly(2,6-bis[3-(9H-carbazol-9-yl)phenyl]pyridine) (P(dCzPP))) and copolymers (P(dCzPP2-co-ED2), P(dCzPP2-co-ED1), P(dCzPP2-co-ED-OH2), and P(dCzPP2-co-ED-OH1)) are synthesized electrochemically. The anodic P(dCzPP2-co-ED2) copolymer with dCzPP:3,4-ethylenedioxythiophene (EDOT) = 2:2 feed molar ratio shows high transmittance change (ΔT%) and colouration efficiency (η), which are measured as 33.3% and 108.7 cm2 C−1 at 1000 nm, respectively. The P(dCzPP2-co-ED2) film shows three kinds of colour variations from neutral to oxidation state, P(dCzPP2-co-ED2) film is reddish brown at 0.0 V, gray blue at 0.6 V, and blue at 1.4 V. Electrochromic devices (ECDs) are composed of P(dCzPP), P(dCzPP2-co-ED2), P(dCzPP2-co-ED1), P(dCzPP2-co-ED-OH2), and P(dCzPP2-co-ED-OH1) as anodically-colouring polymers, and poly(3,3-diethyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepine) (PProDOT-Et2) as cathodically-colouring polymers. Characterizations of five devices are performed using cyclic voltammetry (CV) and UV–Vis spectroscopy. P(dCzPP2-co-ED-OH2)/PProDOT-Et2 ECD shows light grey at 0.0 V, grey-blue at 0.6 V, and blue at 1.8 V. Moreover, P(dCzPP2-co-ED-OH2)/PProDOT-Et2 ECD presents high ΔT (30.9%) and high η (591 cm2 C−1) at 583 nm. Five ECDs have satisfactory optical memory and redox stability.