On heating a semiconductor:

The energy band diagrams for three semiconductor samples of silicon are as shown. We can then assert that :-

Is the ionisation energy of an isolated free atom different from the ionisation energy for the atoms in a crystalline lattice?

The forbidden energy gap in $Ge$ is $0.72\,eV$. Given,$hc = 12400\,eV\cdot\mathring{A}$. The maximum wavelength of radiation that will generate an electron-hole pair is..........$\mathring{A}$.

Carbon, silicon, and germanium atoms have four valence electrons each. Their valence and conduction bands are separated by energy band gaps represented by $(E_g)_C$, $(E_g)_{Si}$, and $(E_g)_{Ge}$ respectively. Which one of the following relationships is true in their case?

If the energy gap of a substance is $5.4 \ eV$,then the substance is