【International Papers】Vertical van der Waals heterojunction diodes comprising 2D semiconductors on 3D β-Ga₂O₃

      Researchers from the Department of Electrical and Systems Engineering of University of Pennsylvania and School of Electrical, Computer, and Energy Engineering of Arizona State University have published a dissertation titled " Vertical van der Waals heterojunction diodes comprising 2D semiconductors on 3D β-Ga₂O₃" in the scientific journal Nanoscale.

Abstract

      Wide bandgap semiconductors such as gallium oxide (Ga₂O₃) have attracted much attention for their use in next-generation high-power electronics. Although single-crystal Ga₂O₃ substrates can be routinely grown from melt along various orientations, the influence of such orientations has been seldom reported. Further, making rectifying p–n diodes from Ga₂O₃ has been difficult due to lack of p-type doping. In this study, we fabricated and optimized 2D/3D vertical diodes on β-Ga₂O₃ by varying the following three factors: substrate planar orientation, choice of 2D material and metal contacts. The quality of our devices was validated using high-temperature dependent measurements, atomic-force microscopy (AFM) techniques and technology computer-aided design (TCAD) simulations. Our findings suggest that 2D/3D β-Ga₂O₃ vertical heterojunctions are optimized by substrate planar orientation (−201), combined with 2D WS₂ exfoliated layers and Ti contacts, and show record rectification ratios (>10⁶) concurrently with ON-Current density (>10³ A cm⁻²) for application in power rectifiers.

Paper Link：https://pubs.rsc.org/en/content/articlelanding/2023/NR/D3NR01987J#fn1