Improving electrochromic performance of panchromatic all-in-one devices by retarding interfacial molecular aggregation/degradation in anode electrode

Abstract

In this work, a well-known hole conductor spiro-OMeTAD was introduced into viologen-based all-in-one electrochromic devices (ECDs) as anode material, which exhibited panchromatic switching between colorless and truly black with efficient performance, involving fast response speed (around 0.5 s for both coloring and bleaching processes), high optical contrast (over 90% throughout the whole visible region), and high coloration efficiency (450.26 cm 2 C −1 at 514 nm, 248.31 cm 2 C −1 at 607 nm and 315.51 cm 2 C −1 at 888 nm). Highly stability was achieved with less than 10% decay in optical contrast after 10000 cycles switching at 514 nm and 607 nm. Moreover, ECDs based on spiro-OMeTAD/HV had a wide working temperature window, and operated efficiently under both low-temperature below −40 °C and high-temperature up to 60 °C. Most importantly, the suppression of the interfacial molecular aggregation and degradation on anode electrode in viologen-based all-in-one electrochromic devices was demonstrated to be crucial for long-term switching stability for the first time. • spiro-OMeTAD was introduced into panchromatic all-in-one ECDs toward enhanced performance. • The present ECDs showed high optical contrast, fast switch and long cycle stability. • Anode interfacial molecular aggregation and degradation in all-in-one ECDs was reported for the first time.