Visible and near-infrared electrochromic thiophene–diketopyrrolopyrrole polymers

Abstract

A series of low bandgap polymers containing thiophene and diketopyrrolopyrrole (DPP) units were synthesized and their electrochromic (EC) properties were investigated. It was found that the ratio (R da ) of thiophene to DPP units correlates to the EC properties, in particular optical contrast (DT) and coloration efficiency (CE) in the visible and near-infrared spectral regions (e.g., 1310 nm). At the wavelength of 1310 nm, the CE of polymer P2 (R da ¼ 3 : 1) and DT of polymer P4 (R da ¼ 4 : 1) reached the high values of 1383 cm 2 C À1 and 81.5%, respectively. Polymer P3 (R da ¼ 3.5 : 1) had a relatively short switching time of 1.24 s from the doped state to neutral state. Colors of polymer films changed reversibly between green or blue (neutral state) and grey (doped state) upon the redox cycling.

Bioinspired Dynamically Switchable PANI/PS‐b‐P2VP Thin Films for Multicolored Electrochromic Displays with Long‐Term Durability

“…It clearly shows that the PPP-2 thin film exhibited the widest tunable spectral range with the reversible color change from medium slate blue to sandy brown. More colors than PANI-based, [47][48][49] organic, [50][51][52] and inorganic [53,54] electrochromic materials have been achieved, as shown in Table S3, Supporting Information.…”

“…It clearly shows that the PPP-2 thin film exhibited the widest tunable spectral range with the reversible color change from medium slate blue to sandy brown. More colors than PANI-based,[47][48][49] organic,[50][51][52] and inorganic[53,54] electrochromic materials have been achieved, as shown in TableS3, Supporting Information.Transmittance spectra of the films at different potentials during CV cycling were further studied. Figure5a-cshows the UV-vis transmission spectra of P-1, P-2, and P-3 thin films during the above-mentioned CV cycling, and Figure5a′-c′ are the transmittances of the PPP-1, PPP-2, and PPP-3 thin films accordingly.…”

Processable Thiophene‐Based Polymers with Tailored Electronic Properties and their Application in Solid‐State Electrochromic Devices Using Nanoparticle Films

“…[ 17 ] Among conjugated polymers, thiophene‐based materials (TMs) have emerged as one of the most promising classes of organic electrochromic materials. [ 18–20 ] A key advantage of TMs stems from the wide possibility of controlling their structure and manipulating their morphology, which allows modifying ad hoc their chemical–physical properties, resulting in a fine‐tuning of polymer's bandgap and color. [ 21–29 ] Although most works reported in the literature focus on the effects of structural changes on the electrochromic properties of materials, less attention has been paid to describing the effect of their nanostructuration in solid‐state EC devices.…”

Synthesis and characterization of novel donor–acceptor type electrochromic polymers containing diketopyrrolopyrrole as an acceptor and propylenedioxythiophene or indacenodithiophene as a donor

“…[13][14][15][16][17] The color changes of these D-A type polymers can be easily controlled through the facile manipulation of the positions and intensities of absorption peaks by regulating the D-A ratio as well as the chemical constitution of the polymers. [18][19][20][21] Indaceno[1,2-b:5,6-b 0 ]dithiophene (IDT), owning thiophenebased fused heteroacenes, has evolved into a versatile building block for organic optoelectronic materials, such as polymer photovoltaic cells and eld-effect transistors. [22][23][24][25][26] Owing to its larger coplanar fused structure, the degree of p electron delocalization is extended, endowing it with a more electron-rich structure, which can be served as a good electron donor.…”

“…37 Recent studies take more attention to use the DPP-based conjugated polymers as electrochromic materials with attractive electrochemical and electrochromic switching properties. 18,[38][39][40][41] Inspired with the unique electron-withdrawing characteristic of the DPP unit, to the best of our knowledge, the studies about electrochromism of IDT/DPP containing conjugated donor-acceptor polymers are scarce.…”