In a junction diode,the holes are due to

In an $n$-type semiconductor, electrons are majority charge carriers and holes are minority charge carriers. The charge of an $n$-type semiconductor is

In $n$-type semiconductor,electrons are majority charge carriers,but it does not show any negative charge. The reason is:

$A$ pure $Si$ crystal has $5 \times 10^{28}$ atoms $m^{-3}$. It is doped with $1 \, ppm$ concentration of pentavalent $As$. The number of holes is (Take $n_i = 1.5 \times 10^{16} \, m^{-3}$)

In pure silicon at $300 \ K$ temperature,the concentration of electrons $n_e$ and holes $n_h$ is $1.5 \times 10^{16} \ m^{-3}$. By doping with Indium,$n_h$ is increased to $4.5 \times 10^{22} \ m^{-3}$. Calculate the concentration of electrons $n_e$ in the doped silicon.

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