Low effective barrier height of GaOx tunnel barrier in metal/semiconductor hybrid junctions

Abstract

We measured the resistance-area products (RAs) in Fe/GaOx/n-(Al)GaAs junctions with respect to the GaOx thickness d. A good linear relation was observed in the log(RA)-d plot, indicating a high-quality tunnel junction. We found that the effective barrier height ϕ in the Fe/GaOx/AlGaAs was very low at 0.10 eV at room temperature. Such a low ϕ with excellent tunability in RA strongly suggests that GaOx is a promising tunnel-barrier material for GaAs-based spin-utilized devices.