Question

A single crystal intrinsic semiconductor is at a temperature of $300K$ with effective density of states for holes twice that of electrons. The thermal voltage is $26mV$.The intrinsic Fermi level is shifted from mid-bandgap energy level by

• A. $18.02meV$
• B. $13.45meV$
• C. $9.01meV$
• D. $26.90meV$

Answer 1

The correct option is C $9.01meV$

Ans : (d)

$\frac{E_c+E_v}{2}-E_{Fi}=\frac{kT}{2}\ln \left(\frac{N_c}{N_v}\right)(\therefore N_c=\frac{N_v}{2})$
$=\frac{0.026}{2}\ln 0.5=-9.01meV$