Thiazolothiazole-Containing Conjugated Polymer with Electrochromism and Electrofluorochromism-Based Dual Performance for a Flip-Flop Molecular Logic Gate

Abstract

Dual-performance devices based on electrochromism and electrofluorochromism have recently gained much attention in display technology. However, getting electrochromism and electrofluorochromism from the same material is very challenging. Herein, we have synthesized a low-band-gap donor− acceptor conjugated thiazolothiazole-containing organic polymer, P-TzTz, that exhibited a quasi-reversible single-electron reduction to demonstrate a pale yellow-to-black (NIR region) electrochromism and a red-to-quenched electrofluorochromism at a low potential window of −1.7 to +0.6 V with suitable electrochromic/electrofluorochromic parameters and stability. Possible redoxinduced modulation of π−π* and intramolecular charge transfer in the P-TzTz polymer, which was validated through density functional theory calculations, interplayed the key role of tunable absorption from vis to NIR and on−off fluorescence switching. Finally, mimicking a flip-flop logic gate model with optical memory functions was also demonstrated by taking the potentials as inputs and electrochromic and electrofluorochromic dual performance signals as outputs.

Hydrogen-Bonded Organic Framework-Polyoxometalate-Based System for Electrochromic Devices

“…The coloration efficiency (η CE ) can better describe the performance of optical density (ΔOD) with injected electrons ( Q ) . The η CE can be derived from the slope of the optical density change vs injected electron plot according to eq η normalC normalE = normalΔ O D Q = log ( T b T c ) Q …”

Reversible Electrochromic/Electrofluorochromic Dual Switching in Zn(II)-Based Metallo-Supramolecular Polymer Films

“…Then, all TPA cores are oxidized to TPA •+ at 1.6 V vs Ag/Ag + . So, the absorption generated at 900 nm at 1.6 V is caused by the bipolaron formation in the polymer backbone, 50,64 which resulted in a strong chromic transition from yellow to green and significant decay in transmittance, as shown in the photograph (Figure 4b). The film generated the original color once the voltage is reversed to the normal state.…”

“…47 Most recently, Halder et al reported a thiazolothiazole-based conjugated polymer as an effective candidate with EC/EFC characteristics. 50 Corrente et al also reported benzothiadiazole-arylamine mixed-valence compounds exhibiting EC/EFC dual functions. 51 However, our group is interested in metallo-supramolecular polymers (MSPs), as they are considered an advanced class of materials for modern device technology.…”

“…According to previous literature reviews, most of the reported EC/EFC active molecules are small organic molecules such as photoredox-active thiophene or TPA derivatives, hydrogels of substituted thiazolothiazole derivatives, and carboxylic acid-substituted terpyridine. − Wang et al introduced an interesting approach for creating dual EC/EFC functionality in a device composed of WO 3 /FTO and copper nanocluster/FTO, where WO 3 served as an EC layer and the copper nanocluster provided photoinduced luminescence . Most recently, Halder et al reported a thiazolothiazole-based conjugated polymer as an effective candidate with EC/EFC characteristics . Corrente et al also reported benzothiadiazole-arylamine mixed-valence compounds exhibiting EC/EFC dual functions …”

Poly (Aryl Amino Ketone/Sulfones) with Obvious Electrochromic Effect Prepared by One-Step Low-Cost and Facile Synthesis

“…The switching time T b 0.9 and T c 0.9 , which was defined as the time to switch between two different color states after voltage, switching reached 90% of the complete absorbance change and was determined using absorbance change plots (Figure 6). All of these polymers showed relatively acceptable switching times (below 9 s), and their bleaching times Tb 0.9 were all shorter than the coloring times Tc 0.9 , which is a common phenomenon even though there were existing counterexamples in some compound systems [24,25]. This indicates that the charge injection process was slower than extraction, which could be attributed to the congregation of the polymer film surface, which increased the potential barrier of oxidation and led to a slower dynamic process, where the path of charge extraction was faster with fewer obstacles than injection.…”