Free‐electron electrochromic modulation in crystalline LixWO3

The reflective and absorptive contributions to the optical modulation in sputter‐deposited thin films of crystalline LixWO3 have been determined as a function of lithium concentration (0 466 °C, the reflective component decreases. The lithium concentration dependence of the absorption coefficients supports the hypothesis that absorption in crystalline LixWO3 arises from free‐electron scattering.