Fig. 2. (a) Absorption spectrum of a dye-sensitized photoelectrochromic cell before (bleached) and after (colored) illumination at an intensity of ∼75 mW cm⁻² for 1 min. The absorption of the dye/TiO₂ dominates the “bleached” state, while Li_xWO₃ is responsible for most of the absorbance in the colored state. Reprinted with permission from ref. 16. Copyright 1996, Springer Nature. (b) Transient optical transmittance at 788 nm of a photoelectrochromic cell with the structure shown in the inset. The cell is placed under a variable load and illuminated with a white-light LED source (4 mW cm⁻²). Reprinted with permission from ref. 19. Copyright 2009, American Chemical Society.