【Device Papers】Growth of tetragonal PtO by molecular-beam epitaxy and its integration into β-Ga₂O₃ Schottky diodes

      Researchers from the Cornell University have published a dissertation titled " Growth of tetragonal PtO by molecular-beam epitaxy and its integration into β-Ga₂O₃ Schottky diodes" in APL Materials.

Abstract

      We demonstrate the epitaxial growth of tetragonal platinum monoxide (PtO) on MgO, TiO₂, and β-Ga₂O₃ single-crystalline substrates by ozone molecular-beam epitaxy. We provide synthesis routes and derive a growth diagram under which PtO films can be synthesized by physical vapor deposition. A combination of electrical transport and photoemission spectroscopy measurements, in conjunction with density functional theory calculations, reveal PtO to be a degenerately doped p-type semiconductor with a bandgap of E_g ≈ 1.6 eV. Spectroscopic ellipsometry measurements are used to extract the complex dielectric function spectra, indicating a transition from free-carrier absorption to higher photon energy transitions at E ≈ 1.6 eV. Using tetragonal PtO as an anode contact, we fabricate prototype Schottky diodes on n-type Sn-doped β-Ga₂O₃ substrates and extract Schottky barrier heights of ϕ_B > 2.2 eV.

DOI：

https://doi.org/10.1063/5.0274229