Electronic Devices and Circuits - Engineering

Q1:

A sample of N-type semiconductor has electron density of 6.25 x 1018/cm3 at 300k. If the intrinsic concentration of carriers in this sample is 2.5 x 1013/cm3 at this temperature the hole density works out to be

A 106/cm3

B 108/cm3

C 1010/cm3

D 10l2/cm3

ANS:B - 108/cm3

Ni^2 = Ne*Np.

Np = Ni^2 / Ne,
Np = (2.5x10^13)^2 / 6.25x10^18,
Np = 10^8.