All-solid-state proton-based tandem structures for fast-switching electrochromic devices

All-solid-state electrochromic devices can be used to create smart windows that regulate the transmittance of solar radiation by applying a voltage. However, suffer from limited ion diffusion speed, which leads slow colouration and bleaching processes. Here we report fast-switching are based on an all-solid-state tandem structure use protons as diffusing species. We tungsten trioxide (WO3) material, poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) solid-state proton source. This exhibits low contrast ratio (that is, difference between off transmittance); however, add solid polymeric electrolyte layer top PEDOT:PSS, provides sodium ions PEDOT:PSS pumps WO3 through exchange. The resulting exhibit high ratios (more than 90% at 650 nm), fast responses (colouration in 0.7 s 65% 0.9 7.1 s), good efficiency (109 cm2 C−1 670 nm) excellent cycling stability (less 10% degradation after 3,000 cycles). also fabricate large-area (30 × 40 cm2) flexible devices, illustrating scaling potential approach. Solid-state structures species ratios, responses, stability.