Intrinsic Semiconductors

Fermi energy level for intrinsic semiconductors lies at _____ of the band gap.

Fermi energy level for intrinsic semiconductors lies at middle of the band gap.

Draw energy band diagram of p & n type semiconductors. Also write two differences between p and n type semiconductors. 

Fermi energy level for intrinsic semiconductors lies.

Draw the energy band diagram when intrinsic semiconductor $\left(\mathrm{Ge}\right)$ is doped with impurity atoms of Antimony $\left(\mathrm{Sb}\right)$. Name the extrinsic semiconductor so obtained and majority charge carriers in it.

In a pure semiconductor, electric current is due to_________.

In a p–type semiconductor, the concentration of holes is$2 \times {10}^{15} {\mathrm{cm}}^{-3}$  The intrinsic carrier concentration is$2 \times {10}^{10} {\mathrm{cm}}^{-3}$ . The concentration of electrons will be.

Assertion : An n-type semiconductor has a large number of electrons but still it is electrically neutral.

 Reason : An n-type semiconductor is obtained by doping an intrinsic semiconductor with a pentavalent impurity. 

The conductivity of a semiconductor sample having electron concentration of $5\times {10}^{18} \mathrm{electrons} {\mathrm{m}}^{-3}$, hole concentration of $5\times {10}^{19} \mathrm{holes} {\mathrm{m}}^{-3}$, electron mobility of $2.0\mathrm{ }{\mathrm{m}}^2\mathrm{ }{\mathrm{V}}^{-1}\mathrm{ }{\mathrm{s}}^{-1}$ and hole mobility of $0.01 {\mathrm{m}}^2\mathrm{ }{\mathrm{V}}^{-1}\mathrm{ }{\mathrm{s}}^{-1}$ is
(Take charge of an electron as $1.6\times {10}^{-19} \mathrm{C}$ )
 

If the mobility of electron in an n-type semiconductor is $3850 {\mathrm{cm}}^2{\mathrm{V}}^{-1}{\mathrm{s}}^{-1}$, then determine the density of donor atoms to be added to intrinsic germanium specimen to make it an n-type semiconductor of conductivity $5 \mathrm{mho}/\mathrm{cm}$

A piece of copper and the other germanium are cooked from room temperature at $80\mathrm{K}$, then which of the following would be a correct statement?

When the electrical conductivity of a semiconductor is due to the breaking of its covalent bonds, then the semiconductor is said to be

The mobility of free electrons is greater than that of free holes because

The truth table of a logic gate is given as

What is the gate?

The current density $\left(J\right)$ for an intrinsic semiconductor is given by which of the following equations:

When the conductivity of a semiconductor is only due to breaking of covalent bonds, the semiconductors is called:

A pure $Si$ crystal has $5\times {10}^{28}$ atoms ${\mathrm{m}}^{-3}.$ It is doped by $1 \mathrm{ppm}$ concentration of pentavalent $\mathrm{As}$. The number of holes is (approximately). (Given that$\left.n_i=1.5\times {10}^{16} {\mathrm{m}}^{-3}\right)$

Calculate the conductivity of pure silicon at room temperature when concentration of carrier is $1.6\times {10}^{10}$ per $-{\mathrm{cm}}^3$
Take ${\mu }_{\mathrm{e}}=1500 {\mathrm{cm}}^2/\mathrm{volt}-\sec ,$ and ${\mu }_{\mathrm{h}}=500$ ${\mathrm{cm}}^2/\mathrm{volt}-\sec$ at room temp.

When the electrical conductivity of a semi-conductor is due to the breaking of its covalent bonds, then the semiconductor is said to be

At absolute zero temperature, intrinsic Germanium and intrinsic Silicon are