If ${n_e}$ and ${n_h}$ are the number of electrons and holes in a semiconductor heavily doped with phosphorus,then

Which of the following dopants is used in germanium to form an $n$-type semiconductor?

Pure $Si$ at $500\,K$ has equal number of electron $(n_e)$ and hole $(n_h)$ concentrations of $1.5 \times 10^{16}\,m^{-3}$. Doping by indium increases $n_h$ to $4.5 \times 10^{22}\,m^{-3}$. The doped semiconductor is of

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:

In a $P$-type semiconductor,there is

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