Fermi level movement for n- and p-GaAs interfaces: Effects of temperature and dopant concentration

Abstract

Photoemission studies demonstrate that temperature and dopant concentration dependent movement of the surface Fermi level is controlled by coupling between adatom‐induced and bulk states. At a low temperature for lightly doped n‐ or p‐GaAs, initial band bending inhibits tunneling and E_F remains near the band edges until the onset of metallicity. For heavy doping, greater band bending reflects a thinner depletion region. Thermal cycling for 20≤T≤300 K for low coverages demonstrates that band bending is reversible.