Table 1.
Bandgap characteristics of some insulators, semiconductors and metals
| Material | Bandgap (eV) | me (x m0) | mh (x m0) | NV at 300°K (cm−3) | Nc at 300°K (cm−3) | No. of atoms/molecules in 1.0 cm3 | ni (300°K, cm−3) | Fraction of atoms providing conduction electrons | Conductivity [σ (S/m), 20 °C] | Conductivity compared to pure silicon |
|---|---|---|---|---|---|---|---|---|---|---|
| Insulators | ||||||||||
| Diamond (undoped) | 5.47 | – | – | – | – | 1.754e23 | 0 | 0 | ~ 1e−16 to ~ 1e−18 | 2.30e−13 to 2.30e−15 |
| Silicon dioxide | 8.9 | – | – | – | – | 2.204e22 | 0 | 0 | ~ 1e−16 to ~ 1e−18 | 2.30e−13 to 2.30e−15 |
| Semiconductors | ||||||||||
| Germanium (undoped) | 0.67 | 0.55 | 0.34 | 4.97e18 | 1.02e19 | 4.41e22 | 1.81e13 | 4.1e−10 | 2 × 100 | 4.60e3 |
| Silicon (undoped) | 1.12 | 1.1 | 0.81 | 1.83e19 | 2.89e19 | 5.00e22 | 1.02e10 | 2.0e−13 | 4.35e−4 | 1.0 |
| Gallium arsenide (undoped) | 1.42 | 0.067 | 0.47 | 8.08e18 | 4.35e17 | 2.21e22 | 2.59e6 | 1.2e−16 | 1e−6 | 2.30e−3 |
| Conductors | ||||||||||
| Gold | – | – | – | 5.8978e22 | 5.8978e22 | 1 | 4.10e7 | 9.43 × 1010 | ||
| Silver | – | – | – | 5.8575e22 | 5.8575e22 | 1 | 6.30e7 | 1.45 × 1011 | ||
| Copper | – | – | – | 8.4661e22 | 8.4661e22 | 1 | 5.96e7 | 1.37 × 1011 | ||