Kim Yong Min, Li Xinlin, Kim Keon-Woo, Kim Se Hyun, Moon Hong Chul
Department of Chemical Engineering, University of Seoul Seoul 02504 Republic of Korea
College of Electromechanical Engineering, Qingdao University Qingdao 266071 China.
RSC Adv. 2019 Jun 20;9(34):19450-19456. doi: 10.1039/c9ra02840d. eCollection 2019 Jun 19.
Finding a new, effective anodic species is a challenge for achieving simpler low-voltage tungsten trioxide (WO)-based electrochromic devices (ECDs). In this work, we utilize tetrathiafulvalene (TTF) and demonstrate its reversible redox behaviors as an electrolyte-soluble anodic species. The concentration of TTF in the electrolyte is varied to optimize device performance. When the TTF concentration is low (0.01 M), a smaller maximum transmittance difference (Δ ∼ 34.2%) and coloration efficiency ( ∼ 59.6 cm C) are measured. Although a better performance of Δ ∼ 93.7% and ∼ 74.5 cm C is achieved at 0.05 M TTF, the colored state could no longer return to its original form. We conclude that 0.03 M of TTF is the appropriate concentration for high-performance WO ECDs with high optical contrast and reversible EC behaviors. The irreversible EC transition at high concentrations of TTF is attributed to the agglomeration of TTF molecules.
找到一种新型、有效的阳极物种是实现更简单的基于三氧化钨（WO）的低压电致变色器件（ECD）的一项挑战。在这项工作中，我们使用了四硫富瓦烯（TTF），并证明了其作为一种可溶于电解质的阳极物种的可逆氧化还原行为。改变电解质中TTF的浓度以优化器件性能。当TTF浓度较低（0.01 M）时，测得的最大透过率差较小（Δ ∼ 34.2%）且显色效率较低（ ∼ 59.6 cm C）。尽管在0.05 M TTF时实现了更好的性能，Δ ∼ 93.7%和 ∼ 74.5 cm C，但着色状态不再能恢复到其原始形式。我们得出结论，0.03 M的TTF是具有高光学对比度和可逆电致变色行为的高性能WO ECD的合适浓度。高浓度TTF下不可逆的电致变色转变归因于TTF分子的团聚。
