1. Find the resistivity of an intrinsic semiconductor with intrinsic concentration of 2.5 × 1019 per m3. The mobilities of electrons and holes are 0.40 m2/ V-s and 0.20 m2/ V-s.
Sol: Given data are:
Intrinsic concentration (ni) = 2.5 × 1019/m3
Mobility of electrons (μn) = 0.40 m2/V-s
The mobility of holes (μp) = 0.20 m2/V-s
The conductivity of an intrinsic semiconductor (σi) = nie[μn + μp]
2. Calculate the number of donor atoms per m3 of n-type material having resistivity of 0.25 Ω-m, the mobility of electrons is 0.3 m2/V-s.
Sol: We know:
[Since n = number of free electron per m3 ≈ number of donor atoms in n-type]
3. At ...