The Hall effect on the surface of germanium crystals cleaved in liquid helium
Vul B.M., Zavaritskaya E.I.
When germanium crystals are cleaved in liquid helium the freshly formed surface captures, on the broken bonds, electrons from the near-surface germanium layer, leaving holes in the valence band. Measurements of the Hall effect show that the concentration of free holes in the near-surface layer and, accordingly, the electron concentration on the surface are approximately 1013 cm ~2. The hole mobility is μ ~ 300 cm2/V sec. The overall physical picture is the same as that observed on the interface of germanium bicrystals.