Characterization of Porous WO₃ Electrochromic Device by Electrochemical Impedance Spectroscopy

Figure 2

SEM images showing the porous structure on anodic tungsten oxide when tungsten was anodized in 0.4 wt.% NaF electrolyte, at 25°C for 1 hr and voltages of (a) 20 V, (b) 40 V, (c) 60 V, (d) 80 V, (e) 100 V, (f) 120 V, (g) 140 V, and (h) 160 V were applied.

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