Electron Band Alignment at Interfaces of Semiconductors with Insulating Oxides: An Internal Photoemission Study
Figure 4
Semilogarithmic plot of the quantum yield of electron IPE from Si as a function of photon energy measured on Si/Al2O3/Au samples with an as-deposited 12 nm thick amorphous (a) ALD Al2O3 layer, as compared to the polycrystalline (γ-phase) Al2O (same samples) obtained by annealing at 1000°C (filled symbols). Vertical arrows indicate energies of direct optical transitions in the Si substrate crystal acting as the source of photoelectrons as well as the onset of intrinsic photoconductivity (the bandgap, ) of a-Al2O3.
