Electrochemical pretreatment of electrochromic WO3 films gives greatly improved cycling durability

Publication date: 1 May 2018
Source:Thin Solid Films, Volume 653
Author(s): Miguel A. Arvizu, Hui-Ying Qu, Gunnar A. Niklasson, Claes G. Granqvist
Electrochromic WO3 thin films have important applications in devices such as smart windows for energy-efficient buildings. Long-term electrochemical cycling durability of these films is essential and challenging. Here we investigate reactively sputter-deposited WO3 films, backed by indium–tin oxide layers and immersed in electrolytes of LiClO4 in propylene carbonate, and demonstrate unprecedented electrochemical cycling durability after straight-forward electrochemical pretreatments by the application of a voltage of 6 V vs. Li/Li⁺ for several hours.