Table 1 Morphology, density, diameter, length, thickness, and average aspect ratio of the grown ZnO structures
Substrate | Substrate position | Temperature (°C) | Morphology | Density (cm −2 ) | Diameter of nanorods/nanoneedles (nm) | Length of nanorods (nm) | Thickness (nm) | Average aspect ratio |
|---|---|---|---|---|---|---|---|---|
SL graphene on SiO2/Si | 90° inclined | 600 | Non-continuous nanoclusters | - | - | - | ~93 | - |
This work | 90° inclined | 800 | A mixture of vertically non-aligned and aligned nanorods | 1.2 × 109 | 37–74 | 93–574 | ~40 (base structure) | ~5.1 |
90° inclined | 1,000 | Randomly dispersed clusters | - | - | - | - | - | |
ML graphene on SiO2/ Si | 90° inclined | 600 | Continuous clusters/layer | - | - | - | ~1,062 | - |
This work | 90° inclined | 800 | Nanorods | 7.0 × 109 | <150 | <540 | ~90 (base structure) | ~2.8 |
90° inclined | 1,000 | Thin film | - | - | - | ~74 | - | |
ML graphene SiO2/ Si by thermal evaporation [3] | 45° inclined | 600 | Non-continuous nanoclusters | - | - | - | ~200 | - |
45° inclined | 800 | Nanorods | 6.9 × 109 | <150 | <540 | ~50 (base structure) | ~2.8 | |
45° inclined | 1,000 | Thin film | - | - | - | ~60 | - | |
Porous silicon by thermal evaporation [21] | Placed on source boat and facing downward | 800 | Nanorods | 1.2 × 108 | 200–500 | Not stated | - | Not stated |
ML graphene on SiO2/Si by MOVPE [1] | Standard horizontal position | 400 | Nanorods | 4.0 × 109 | 100 ± 10 | 1,000 ± 100 | - | ~10.0 |
600 | Nanoneedles | 8.0 × 109 | 90 ± 20 | 4,000 ± 600 | - | ~44.4 | ||
750 | Nanoneedles | 5.0 × 107 | Not stated | 3,500 ± 500 | - | Not stated |