Alkali metal ion-doped electrochromic films, and methods of making such films, are disclosed. An exemplary electrochromic film comprises a lattice of an oxide of a Group VIII transition metal and a dopant deposited onto the surface of a substrate. The oxide is generated by heating at least one starting material and at least one dopant ion source on the surface of the substrate.
 The United States Government has rights in this invention under Contract No. DE-AC36-08GO28308 between the United States Department of Energy and the Alliance for Sustainable Energy, LLC, the Manager and Operator of the National Renewable Energy Laboratory.