Fig. 1. Structures of photoelectrochemical electric field photoanodes. (a) Flat plate structure; (b) pyramid structure; (c) inverted pyramid structure

Fig. 2. Two-dimensional models of both structures. (a) Pyramid structure height aspect ratio; (b) inverted pyramid structure depth aspect ratio

Fig. 3. Photoanode reflectance for different height aspect ratios (aspect ratio between 0‒2)

Fig. 4. Photoanode reflectance for different depth aspect ratios (aspect ratio between 0‒2)

Fig. 5. Comparisons of reflectance and absorptivity of three structured photoanodes at wavelength of 300‒800 nm. (a) Reflectance comparison; (b) absorptivity comparison

Fig. 6. Comparisons of performance of photoelectrochemical cells with three structures. (a) Comparison of short-circuit current density; (b) power comparison

Fig. 7. Cross-sectional electric field distributions of photoanodes with flat plate, pyramid and inverted pyramid structures at 300, 500 and 800 nm. (a) Flat plate structure; (b) pyramid structure; (c) inverted pyramid structure

Fig. 8. Three-dimensional electric field distributions of photoanodes at 300, 600 and 800 nm. (a) Pyramid structure; (b) inverted pyramid structure