The valence of an impurity added to germanium crystal in order to convert it into a $P-$type semiconductor is

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 $\mu \text{m}$)

When a battery is connected to a $P$-type semiconductor with a metallic wire,the current in the semiconductor (predominantly),inside the metallic wire,and inside the battery is due to which charge carriers respectively?

The conductivity of a pure semiconductor can be increased by

In a semiconductor,the concentration of electrons is $8 \times 10^{14} \text{ cm}^{-3}$ and that of the holes is $5 \times 10^{12} \text{ cm}^{-3}$. The semiconductor is

$A$ $P$-type semiconductor is: