Surface Modification of Porous Photoelectrode Using Etching Process for Efficiency Enhancement of ZnO Dye-Sensitized Solar Cells

Figure 1

Morphology of ZnO films etched by NH₄OH solutions with various etching time; (a) 0 min, (b) 1 min, (c) 2 min, (d) 3 min, and (e) cross-sectional image.

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