Various types of bonds in chemisorption on semiconductors

Summary

The possibility of the formation of various types of bonds between a given atom and a given adsorbent is a characteristic feature of chemisorption. In this respect chemisorption, which is chemical union between a solid and a foreign atom, differs from the usual chemical compounds, which are formed by union between atoms or groups of atoms with formation of molecules, The bond between two atoms (or two groups of atoms) inside a molecule always has a quite definite character, determined unequivocally by the nature of the two components entering into the bond.

The existence of bonds of different types in the chemisorption of the atom A on the ionic crystal MR is determined ultimately by the presence in such a crystal of free electrons and “holes” which fulfill the function of free positive and negative valences respectively and my be drawn (or may not be drawn) into participation in the bond.