The majority charge carriers in $p$-type and $n$-type semiconductors are respectively:

Explain the recombination coefficient of an intrinsic semiconductor and derive the relation $n_i^2 = n_e n_h$.

The process of adding impurities to a pure semiconductor is called

For a $p-$type semiconductor,which of the following statements is true?

In a pure silicon crystal,the electron-hole concentration is $10^{16} \ m^{-3}$ at $301 \ K$. Now,$10^{21}$ atoms of phosphorus are added per cubic metre. The new hole concentration in silicon is (in per $m^3$):

$A$ $P$-type semiconductor has acceptor levels $57 \; meV$ above the valence band. The maximum wavelength of light required to create a hole is (Planck's constant $h = 6.6 \times 10^{-34} \; J \cdot s$, speed of light $c = 3 \times 10^8 \; m/s$)