Figure 1

Macropore morphologies obtained with DMA- and DMF-based electrolytes and different HF and water concentrations. The pores were etched into 20-Ω cm p-Si {100} with nuclei distance of 3 μm and j = 10 mA cm⁻². a) DMF 5%(5.4%) resulted in pores with smooth walls and constant diameter. b) DMF 10%(11%) resulted in pores with rougher walls, larger diameter, and shorter lengths. c) DMA 10%(11%) resulted in pores with smooth walls, constant but bigger diameter, and shorter lengths. d) DMA 10%(3.8%) resulted in pores with geometries nearly identical to that of (a).