Donor−Acceptor Polymer Electrochromes with Tunable Colors and Performance

Abstract

To demonstrate the effect of donor (D) and acceptor (A) units on the structure-property relationships of electrochromic polymers, design, synthesis, characterization and polymerization of a series of D-A type systems, 1-5, based on thiophene, 3,4-ethylenedioxythiophene, and 3,3didecyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepine as D units and 2,1,3-benzoselenadiazole, 2,1,3benzothiadiazole and 2-decyl-2H-benzo [d][1,2,3]triazole as A units are highlighted. It is found that these units play key roles on the redox behavior, band gap, neutral state color, and the electrochromic performance (stability, optical contrast, coloration efficiency, and switching time) of the system. It is noted that electropolymerization of these D-A systems provides processable low band gap electrochromes, P1-P5, exhibiting high redox stability, coloration efficiency, transmittance and/or contrast ratio and low response time. Furthermore, P1-P5 reflect various hues of blue and green pallets of the RGB color-space in the neutral state. In particular, it is noteworthy that P5 is an excellent blue-to-colorless polymeric electrochrome, which, to our best knowledge, exhibits the highest optical contrast and coloration efficiency among the D-A type systems. The panoramic breadth of the neutral state colors and intriguing features of these polymeric materials further confirm that D-A approach allows engineering tunable electrochromes, which hold promise for commercialization of polymeric RGB electrochromics.

Hybrid Materials and Polymer Electrolytes for Electrochromic Device Applications

“…To address this issue, an important line of recent research on EC polymers concerns the engineering of the band gaps of conjugated polymers to improve cycle life of the EC devices. A commonly strategy is to adopt donor‐acceptor (D‐A) approach 35–43. The D‐A type conjugated polymers have alternating electron rich and electron deficient groups on their backbones.…”

Carbazole based electrochromic polymers with benzoazole units: Effect of heteroatom variation on electrochromic performance

“…Cbz, BN, BS and BSe were synthesized according to procedures from the literature [23]. Syntheses of the polymers (PCBN, PCBS and PCBSe) were achieved by Suzuki reaction between Cbz-donor and BX-acceptors respectively (Figure 1).…”

“…The initial compounds (Cbz, BN, BS and BSe) were prepared and characterized according to the literature [23].…”

Recent Developments in the Synthesis and Applications of 1,2,5-Thia- and Selenadiazoles. A Review

“…Furthermore, these polymers reflect various hues of blue and green pallets of the Red-Green-Blue color-space in the neutral state. 234 Poly(arylenevinylene) derivatives containing, as an acceptor unit, 2,1,3-benzothiadiazole are good electron transporters with low band gap and broad absorption range. It was shown that the vinyl spacer maintains the electron affinity, reduces the band Downloaded by [Laurentian University] at 08:03 25 November 2014 gap and widens the absorption range.…”