Advanced Electrochromic Materials: a (Smart) Window on the World of Tomorrow

The energy demand of buildings can be significantly reduced by integrating energy-efficient technologies that limit overall energy consumption. Smart windows are devices capable of dynamically controlling indoor luminosity and temperature in response to external factors such as weather conditions, seasonal variations, or user preferences. Among the various materials and formulations investigated, electrochromic materials—characterized by their ability to reversibly switch between optical states upon the application of an electric potential—have been extensively studied for smart-window applications. In this work, the mechanisms governing the optical activity of such materials are discussed, with particular emphasis on dual-band formulations, which enable the dynamic and independent control of light and heat supplied to buildings, respectively related to transmitted visible (VIS) and near-infrared (NIR) solar radiation. Finally, the main results of the author’s thesis are presented, highlighting the dual-band electrochromic behavior of a distinctive molybdenum–tungsten mixed oxide formulation, whose potential for this application had never been investigated before, to the best of our knowledge.