Using WO3 as a transparent, optically-passive counter electrode in an unbalanced electrochromic configuration

Abstract Electrochromic cells in a proposed new architecture, called unbalanced configuration, were constructed using poly(2,2-dimethyl-3,4 propylenedioxythiophene) (PolyPRODOT-Me 2 ) as the working electrode and tungsten trioxide (WO 3 ) as the counter electrode. This unbalanced system allowed us to drastically change the electrochromic behavior of WO 3 , using it as an optically-passive transparent material, therefore confirming the potential of this new configuration as a viable alternative in the design of electrochromic devices. Functional electrochromic cells working under a narrow voltage of 1.5 V and reaching an optical contrast of 52% at 566 nm were constructed and tested.