These films were then annealed in a furnace at 400℃ under air to remove the oleic acid ligands that coat the surface of the NCs to improve film conductivity. No structural change was observed using XRD in NC powders annealed under the same conditions, indicating the hexagonal crystal structural and NC morphology are not impacted by the annealing process. These NC thin films were then used as electrodes to study their electrochromic properties.