Question

The intrinsic fermi level in silicon is 12.5 meV below the midgap energy at T = 300K. Then the ratio of effective mass of electron to effective mass of hole is equal to
(Assume KT at T = 300 K is 0.0259 eV)

Answer 1

Given

$E_{Fi}-E_{midgap}=-12.5mV$

But,

$E_{Fi}-E_{midgap}=\frac{3}{4}kTIn\left[\frac{m_p^{\ast }}{m_n^{\ast }}\right]-12.5meV=\frac{3}{4}\times \left(0.0259\right)ln\left(\frac{m_p^{\ast }}{m_n^{\ast }}\right)\frac{m_p^{\ast }}{m_n^{\ast }}=1.9$