Mobilities of electrons and holes in a sample of intrinsic $Ge$ at room temperature are $0.35 \, m^2/V-s$ and $0.18 \, m^2/V-s$ respectively. If the electron and hole densities are each equal to $2.5 \times 10^{19} \, /m^3$,the $Ge$ conductivity will be.....$S/m$ (in $.12$)

$P$-type semiconductors are made by adding which impurity element?

What is the relation between the number density of holes $(n_h)$ and free electrons $(n_e)$ in an intrinsic semiconductor at room temperature?

In a $p$-type semiconductor,the acceptor level is at $50 \text{ meV}$ above the valence band. To produce one hole,the maximum wavelength of the light photon required is (Planck's constant,$h = 6.6 \times 10^{-34} \text{ Js}$ and speed of light in vacuum,$c = 3 \times 10^8 \text{ m/s}$) (in $\mu \text{m}$)

In an $N$-type semiconductor,where are the donor energy levels $E_D$ located?

The mobility of free electrons is greater than that of free holes because