Suppose a pure $Si$ crystal has $5 \times 10^{28}$ atoms $m^{-3}$. It is doped with $1 \text{ ppm}$ concentration of pentavalent $As$. Calculate the number of electrons and holes. $(n_i = 1.5 \times 10^{16} \text{ m}^{-3})$

When germanium is doped with phosphorus,the doped material has

Mobility of electrons in a semiconductor is defined as the ratio of their drift velocity to the applied electric field. If,for an $n$-type semiconductor,the density of electrons is $10^{19} \ m^{-3}$ and their mobility is $1.6 \ m^2/(V \cdot s)$,then the resistivity of the semiconductor (since it is an $n$-type semiconductor,the contribution of holes is ignored) is close to ................ $\Omega \cdot m$.

Which of the following when added as an impurity into silicon produces $n-$type semiconductor?

If $n_e$ and $v_d$ are the number density of electrons and drift velocity in a semiconductor,respectively,what happens when the temperature is increased?

In an $n$-type semiconductor,the Fermi energy level lies