All-in-one Dual-Band Wide Optical Modulation Electrochromic Films

The electron-withdrawing property of the six-unit ring containing three nitrogen atoms in the structure of 2, 4, 6-tris (4-pyridyl)1,3,5-triazine was utilized to form with bipyridine salts two new viologen derivatives, 4, 4', 4''- (1, 3, 5-triazin-2, 4, 6-triyl) tris -1- (but-3-enyl) pyridine) (TPBET) and 4, 4', 4''- (1, 3, 5-triazine-2, 4, 6-triyl) tris 1-(4-vinylbenzylpyridine) (TPSET) were prepared as electrochromic devices (ECDs) with dual-band wide optical modulation. The maximum transmittance modulation of the prepared ECDs in the visible/near-infrared bands reaches 82.46 % and 78.31 %, respectively, and its good stability enables it to maintain the initial transmittance modulation range of 91.6 % after 1,000 cycles, which brings a good prospect for the application of electrochromic smart windows.