Manganese doped nickel oxide thin film with improved electrochromic performance towards smart window application

Electrochromic (EC) smart window can dynamically alter optical property under the electric field, showing great potential in building energy conservation. Nickel oxide (NiO) acts as one of the most promising EC candidates while suffering insufficient reaction sites and low electrical conductivity. Herein, we introduced Mn2+ ions into NiO for the heteroatom doping towards improved EC performance. As expected, NiO–Mn-3 film exhibited optimal transmittance modulation (81.8 %) and fast coloring/bleaching time (3.5/5.1 s), which were considerably related to the improved specific surface area and increased electronic conductivity. Electrochemical characterization confirmed that the enhanced ions diffusion coefficient and lowered resistance delivered a positive impact on boosting the EC property. Mott-Schottky study also confirmed that the heteroatom doping effectively increased the carrier concentration. Our results not only provided important insight into a promising electrode material for EC energy-saving application, but also offered an economic and effective synthetic strategy for other doped metal oxide films.