posted on 2024-01-31, 16:39authored byTaolve Wang, Wei Zhang, Tianhao Li, Qing Xia, Suting Yang, Jianquan Weng, Ke Chen, Wangqiao Chen, Ming Liu, Shiyu Du, Xiao Zhang, Yujie Song
Phthalocyanines
have been widely investigated as electrochromic
materials because of their large conjugated structure. However, they
have shown limited applicability due to their complex electrochromism
mechanism and low solubility in common organic solvents. Replacement
of central metal ions in phthalocyanines affects their stability and
is responsible for various electrochromic phenomena, such as color
change. Herein, the relationship between the electron d-orbital arrangement
in the outermost layer of transition metals and the electrochromic
stability of phthalocyanine derivatives has been investigated. An
enhanced solubility of phthalocyanines in organic solvents was obtained
through the introduction of quaternary tert-butyl
substitution. Electrochromic devices fabricated with transition-metal
phthalocyanine derivatives showed high response speeds and good stability.
The fast color-switching feature between blue/green and blue/purple
makes it a promising candidate for smart windows and adaptive camouflage
applications.