When germanium is doped with phosphorus,the doped material has

Doping of a semiconductor (with small impurity atoms) generally changes the resistivity as follows.

In the energy band diagram of a material shown below,the open circles and filled circles denote holes and electrons respectively. The material is a/an

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

Which of the following statements is true for an $N$-type semiconductor?

$A$ $P$-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 $h = 6.6 \times 10^{-34} \, J-s$, speed of light $c = 3 \times 10^8 \, m/s$, charge of electron $e = 1.6 \times 10^{-19} \, C$)