A newly-designed self-powered electrochromic window

By converting incident light into electric power, self-powered electrochromic window (SP-ECW) can achieve color change in electrochromic layer with no need for external voltage. In this work, a newly-designed SP-ECW is proposed for altering its color between deep blue and colorless state according to on/off state of incident light. The device consists of a working electrode with planar integration of photovoltaic (PV) and electrochromic (EC) elements on one electrode, a platinum counter electrode and a redox electrolyte comprising Br-/Br (3) (-) couple. A high transmittance modulation of 41% at 582 nm is obtained. Electrical energy converted from light is not only sufficient to drive the device, but also can be outputted to the external circuit.