Theoretical Insights for Improving the Schottky-Barrier Height at the Ga2O3/Pt Interface

In this work, we study the Schottky-barrier height (SBH) at the junction between β-Ga2O3 and platinum, a system of great importance for the next generation of high-power and high-temperature electronic devices. Specifically, we obtain interfacial atomic structures at different orientations using our structure-matching algorithm and compute their SBH using electronic structure calculations based on hybrid density-functional theory. The orientation and strain of platinum are found to have little impact on the barrier height. In contrast, we find that decomposed water molecules (H.OH), which could be present at the interface from Ga2O3 substrate preparation, has a strong influence on the SBH, in particular in the (2¯01) orientation. The SBH can range from approximately 2 eV for a pristine interface to nearly zero for a full H.OH coverage. This result suggests that a SBH of approximately 2 eV can be achieved for the Ga2O3(2¯01)/Pt junction using the substrate-preparation methods that can reduce the amount of adsorbed water at the interface.