Table 1.
Summary of surface wettability, surface roughness analysis and geometrical parameters of nanopillars of the bSi surfaces
| Parameters | bSi-1 | bSi-2 | bSi-3 |
|---|---|---|---|
| Wettability | |||
| Water contact angle, θ (degrees) | 130.8 ± 3.2 | 100.9 ± 1.6 | 8.1 ± 1.2 |
| Surface roughnessa | |||
| Average roughness (nm) Ra | 82.3 ± 29.6 | 110.3 ± 27.6 | 124.7 ± 17.7 |
| Root-mean-square roughness (nm) Rq | 103.7 ± 37.3 | 136.5 ± 34.2 | 156.8 ± 22.2 |
| Geometrical parametersb | |||
| Height (nm) | 836.8 ± 91.2 | 657.9 ± 74.3 | 1063.2 ± 159.5 |
| Tip width (nm) | 100.1 ± 36 | 110.3 ± 26.9 | 120.5 ± 17.1 |
| Interpillar distance (nm) | 153.1 ± 55.3 | 135.6 ± 33.9 | 197.4 ± 28.0 |
| Density (number of tips per µm2) | 11 ± 4 | 10 ± 3 | 8 ± 2 |
| Aspect ratio | 8.4 ± 2.9 | 6.0 ± 1.8 | 8.8 ± 2.0 |
| Chemical compositionc | |||
| Si/SiO2 | 1.2 | 1.3 | 2.2 |
| Si (total) (At.%) | 26 | 27 | 35 |
aAFM roughness analysis, 2.5 × 2.5 µm2 scanning areas
bSEM micrographs
cXPS analysis