An $n$-type and a $p$-type silicon semiconductor can be obtained by doping pure silicon with

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

If $N_h$ and $N_e$ are the numbers of holes and conduction electrons in an extrinsic semiconductor,respectively,then:

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 $Ge$ crystals are doped with phosphorus atoms,then it becomes

In a sample of pure silicon, $10^{13} \text{ atoms/cm}^3$ of phosphorus is added. If all donor atoms are active and the electron mobility is $1200 \text{ cm}^2/\text{V}\cdot\text{s}$, what will be the resistivity at $20^\circ\text{C}$ in $\Omega\cdot\text{cm}$?