Bonds in Semiconductors

Bonds in Semiconductors
The atoms of every element are held together by the bonding action of valence electrons. When the bonding takes place, the atom may lose, gain or share valence electrons with other atoms. In semiconductors, bonds are formed by sharing of valence electrons. Such bonds are called co-valent bonds.
Figure 1.1.1
Figure 1.1.1 shows the co-valent bonds among germanium atoms. A Ge atom has 4 valence electrons. Ge atom has a tendency to have 8 electrons in the outer orbit. Each atom shares one valence electron with the neighboring atom and central atom sets up co-valent bond. Valence electrons in a semiconductor are not free.