Surface electronic properties of diamond

The influence of surface states, defects and adsorbates on the electronic p roperties of diamond surfaces are discussed. As far as surface states and r econstructions are concerned the principal crystallographic surfaces, (100) , (111) and (110), are essentially understood in their adsorbate free form and also when terminated by hydrogen. The role of surface defects is addres sed and the correlation between the position of the surface Fermi level and the concentration of surface defects is discussed quantitatively for p-typ e diamond. Hydrogen passivation leads to a negative electron affinity of di amond surfaces due to a dipole layer which is induced by the heteropolar ca rbon-hydrogen bonds of the surface atoms. This aspect is discussed quantita tively. Finally, an experiment in which photoelectron spectroscopy and in s itu conductivity measurements were combined to elucidate the surface conduc tivity of diamond is described and analyzed.