A pure silicon crystal with 5 × 10²⁸ atoms m⁻³ has nᵢ = 1.5 × 10¹⁶ m⁻³. It is doped with a concentration of 1 in 10⁵ pentavalent atoms. The number density of holes (per m³) in the doped semiconductor will be:
1
4.5 × 10³
2
4.5 × 108
3
(\(\frac{10}{3}\))10¹²
4
(\(\frac{10}{3}\))10⁷