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Carbon, silicon and germanium atoms have four valence electrons each. Their valence and conduction bands are separated by energy band gaps represented by $\left(E_g\right)_{\mathrm{C}},\left(E_g\right)_{\mathrm{Si}}$ and $\left(E_g\right)_{\mathrm{Ge}}$ respectively. Which one of the following relationships is true in their case?
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The correct answer is:
$\left(E_g\right)_{\mathrm{C}}\gt\left(E_g\right)_{\mathrm{Si}}$
Carbon, silicon and germanium are semiconductors.
$\begin{aligned}& \left(E_g\right)_{\mathrm{C}}=5.2 \mathrm{eV} \\& \left(E_g\right)_{\mathrm{Si}}=1.21 \mathrm{eV} \\& \left(E_g\right)_{\mathrm{Ge}}=0.75 \mathrm{eV}\end{aligned}$
Thus, $\left(E_g\right)_{\mathrm{C}}\gt\left(E_g\right)_{\mathrm{Si}}$ and $\left(E_g\right)_{\mathrm{C}}\gt\left(E_g\right)_{\mathrm{Ge}}$
NOTE : Elements carbon, silicon and germanium are found in IVA group of periodic table.
$\begin{aligned}& \left(E_g\right)_{\mathrm{C}}=5.2 \mathrm{eV} \\& \left(E_g\right)_{\mathrm{Si}}=1.21 \mathrm{eV} \\& \left(E_g\right)_{\mathrm{Ge}}=0.75 \mathrm{eV}\end{aligned}$
Thus, $\left(E_g\right)_{\mathrm{C}}\gt\left(E_g\right)_{\mathrm{Si}}$ and $\left(E_g\right)_{\mathrm{C}}\gt\left(E_g\right)_{\mathrm{Ge}}$
NOTE : Elements carbon, silicon and germanium are found in IVA group of periodic table.
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