When an $n$-type semiconductor is heated,

In a $P$-type semiconductor, the acceptor level is $57 \, meV$ above the valence band. What is the wavelength of light in $\mathring{A}$ required to create a hole? (Given: $h = 6.6 \times 10^{-34} \, J \cdot s$, $c = 3 \times 10^8 \, m/s$, $1 \, eV = 1.6 \times 10^{-19} \, J$)

In the energy band diagram of a material shown in the figure,the open circles and filled circles denote holes and electrons,respectively. The material is:

$P-$type semiconductor is formed when:

What will be the conductivity of a pure silicon crystal at $300 \ K$? Given that the intrinsic carrier concentration is $1.072 \times 10^{10} \ cm^{-3}$ and at this temperature,the electron mobility $\mu_n = 1350 \ cm^2 / (V \cdot s)$ and hole mobility $\mu_p = 480 \ cm^2 / (V \cdot s)$.

Let ${n_h}$ and ${n_e}$ be the number of holes and conduction electrons respectively in a semiconductor. Then