When a small amount of antimony impurity is added to a germanium crystal,what happens?

When a small amount of impurity atoms are added to a semiconductor,then generally its resistivity

Suppose an $n$-type wafer is created by doping $Si$ crystal having $5 \times 10^{28} \text{ atoms/m}^3$ with $1 \text{ ppm}$ concentration of $As$. On the surface,$200 \text{ ppm}$ Boron is added to create a $p$-region in this wafer. Considering $n_i = 1.5 \times 10^{16} \text{ m}^{-3}$,$(i)$ Calculate the densities of the charge carriers in the $n$ and $p$ regions. $(ii)$ Comment on which charge carriers would contribute largely to the reverse saturation current when the diode is reverse biased.

In a $P$-type semiconductor, the acceptor level is $57 \text{ meV}$ above the valence band. What is the maximum wavelength of light (in $\mathring{A}$) required to create a hole?

For an intrinsic semiconductor,where $n_{h}$ and $n_{e}$ are the number of holes per unit volume and the number of electrons per unit volume respectively,which of the following relations holds true?

$A$ semiconductor doped with a donor impurity is