Facile preparation of WO₃/PEDOT: PSS composite for inkjet printed electrochromic window and its performance for heat shielding

In this study, we have prepared an electrochromic (EC) ink composed of WO₃ nanoparticles and poly (3,4-ethylenedioxythiophene):poly (styrene sulfonate) (PEDOT:PSS). The ink formulation can be processed through inkjet-printing or spray coating to deposit high-quality EC layers. The PEDOT:PSS acts as an conductive binder to connect the WO₃ nanoparticles leading to reduced impedance and better electrochemical properties. The WO₃/PEDOT:PSS (PH1000) exhibits an optical modulation of 54.1%, a response time of 1.1 s, and a coloration efficiency of 83.87 cm²/C. A hybrid type electrochromic device (ECD) incorporated with WO₃/PEDOT:PSS with excellent durability has been fabricated. The performance of WO₃/PEDOT:PSS based ECD for sun shielding property is also evaluated. The ECD can efficiently block the sunlight and reduce solar heat gain. As a result, the indoor temperature can be modulated from 32.7 °C (bleached state) to 29.4 °C (darken state) under illumination.