If $n_e$ and $n_h$ are electron and hole concentrations in an extrinsic semiconductor and $n_i$ is the intrinsic carrier concentration,then:

In an $N$-type semiconductor,where are the donor energy levels $E_D$ located?

In an intrinsic semiconductor,the energy gap $E_{g}$ is $1.2 \; eV$. Its hole mobility is much smaller than electron mobility and independent of temperature. What is the ratio between conductivity at $600 \; K$ and that at $300 \; K$? Assume that the temperature dependence of intrinsic carrier concentration $n_{i}$ is given by $n_{i} = n_{0} \exp \left(-\frac{E_{g}}{2 k_{B} T}\right)$,where $n_{0}$ is a constant.

$P$-type semiconductors are made by adding which impurity element?

In a semiconductor,the number densities of electrons and holes are $8 \times 10^{18} \ m^{-3}$ and $5 \times 10^{18} \ m^{-3}$ respectively. If the mobilities of electrons and holes are $2.3 \ m^2/V \cdot s$ and $0.01 \ m^2/V \cdot s$ respectively,then the semiconductor is:

Pure silicon at $300 \ K$ has equal electron and hole concentration of $1.5 \times 10^{16} \ m^{-3}$. If the hole concentration increases to $3 \times 10^{22} \ m^{-3}$,then the electron concentration in the silicon is