Influence of Fe Doping on the Electrochromic Properties of Co-sputtered V₂O₅ Thin Films

Vanadium pentoxide (V 2 O 5 ) attracts considerable attention in electrochromism due to its multicolor aspects and high ion storage capacity for the counter electrode. In this work, pure and Fe-doped V 2 O 5 films are deposited by radiofrequency magnetron co-sputtering. The influence of Fe doping on the structural and electrochemical properties of V 2 O 5 -based thin films is investigated. Thin films containing up to 7.8 atom % of Fe are obtained without phase impurities. Although this high Fe doping is detrimental to V 2 O 5 electrochromic properties, a proper amount of about 1.7 atom% of Fe leads to an enhancement of V 2 O 5 crystallinity and electrochemical capacity. The higher capacity of a 1.7 atom % Fe-doped V 2 O 5 film is associated with a stronger memory effect property, described as a reversible color persistence in open-circuit conditions. This work contributes to the exploration of Fe doping through co-sputtering and highlights the relevant role of the doping amount on the physicochemical properties of V 2 O 5 .