Determination of the conduction band offset between hydrogenated amorphous silicon and crystalline silicon from surface inversion layer conductance measurements

The presence of an electron rich inversion layer in p-type crystalline silicon (c-Si) at the interface with n-type hydrogenated amorphous silicon (a-Si:H) is experimentally demonstrated from the coplanar conductance of (n) a-Si:H/(p) c-Si structures, which is shown to be very sensitive to the band mismatch between the two semiconductors. The temperature dependence of the corresponding sheet electron density allows to determine with a very good precision the conduction band offset Delta E-C between a-Si:H and c-Si:Delta E-C=0.15 +/- 0.04 eV. (C) 2008 American Institute of Physics.