What is the conductivity of a semiconductor (in `Omega^(-1) m^(-1)`) if electron density `= 5 xx 10^(12) cm^(-3)` and hole density `= 8 xx 10^(13) cm^(-3)`?
`(mu_(e) = 2.3 V^(-1) s^(-1)m^(2), mu_(h) = 0.01 m^(2) V^(-1) s^(-1))`

Options

A. 5.634
B. 1.968
C. 3.421
D. 8.964

Answer

B

Explanation

Given : `mu_e = 2.3 m^2 V^(-1) s^(-1)`
`mu_h = 0.01 m^2 V^(-1) s^(-1) , n_e = 5 xx 10^12 //cm^3`
`=5 xx 10^18 //m^3n_h = 8 xx 10^13//cm^3 = 8 xx 10^19// m^3`.
Conductivity `sigma = e[n_emu_e + n_h mu_h]`
`= 1.6 xx 10^(-19)[5 xx 10^8 xx 2.3 + 8 xx 10^19 xx 0.01]`
`=1.6 xx 10^(-1) [ 11.5 + 0.8]`
`= 1.6 xx 10^(-1) xx 12.3 = 1.968 Omega^(-1) m^(-1)`