Energy saving electrochromic windows from bistable low-HOMO level conjugated polymers

Abstract

Energy saving electrochromic windows were achieved by controlling the interfacial charge transfer using low-HOMO level (<italic>E</italic>_HOMO &lt; −5 eV) π-conjugated polymers (CPs) as bistable electrochromic films and an ionic liquid as the electrolyte layer. It provided a long bistability (&gt;90 min) at the voltage-off state with a high coloration efficiency (879 cm² C⁻¹).