In situ direct determination of band offset and interfacial dipole potential of a laminar ALD-Y2O3 on a p-type GaAs(0 0 1)-4 × 6 surface

Abstract

Using in situ synchrotron-radiation photoelectron spectroscopy, the band offsets and the surface dipole potential energy for cycle-by-cycle atomic layer deposited (ALD) Y2O3 on p-type GaAs(0 0 1)-4 × 6 were studied. We have characterized the electronic property for laminar films. The valence- and conduction-band offsets and interfacial dipole potential energy are approximately 1.75, 2.4, and 0.46 eV, respectively. The dipole direction points outward, showing that Y(+) is located at the topmost layer and the O(−) ions participate in the bonding with the GaAs surface atoms.