Alternating Current‐Driven Electrochromic Devices Based on Benzyl Viologen: AC Frequency Indicator

Electrochromic devices (ECDs) have been extensively studied worldwide due to their promising applications in various fields. To the best of our knowledge, all previously reported ECDs are exclusively driven by direct current (DC), which has been the conventional approach in electrochromic research. In this article, we propose that the ECD driven by alternating current (AC) should be testified. The ECDs were sandwiched in all‐in‐one mode using 1,1′‐dibenzyl‐4,4′‐dipyridine dichloride as electrochromic chromophore. The electrochromic performance of the as‐AC‐driven ECDs was examined as a function of AC frequency from 0.1 to 1000 Hz. It is found that electrochromic based on dibenzyl viologen can work driven by AC, but with some differences from that by DC. The optical contrast is directly proportional to the logarithm value of AC frequency in the range from 0.1 to 1000 Hz, which suggests that the AC‐driven ECD may potentially be useful as a visual indicator for AC frequency.