Robust type-III C3N/Ga2O3 van der Waals heterostructures

Abstract

By combining two-dimensional (2D) materials with different band alignments at the contact interface, van der Waals heterostructures (vdWHs) can achieve multifunctional device applications. Here, through first principles methods, we constructed two C3N/Ga2O3 vdWHs named P↑ and P↓ because of the intrinsic polarization of Ga2O3 to study electronic, interfacial and optical characteristics. We find that the P↑ and P↓ both display a unique kind of band alignment known as broken-gap or type-III. This feature makes them highly suitable for tunnel field effect transistors (TFETs) applications. To the best of our knowledge, the tunnel window of the P↓ is the largest among the theoretical studies, reaching 0.993 eV. The electronic structure and band edge alignment of the C3N/Ga2O3 vdWHs show a weak dependence on strain engineering or external electric field. Normal-to-plane compressive strains effectively enhance the tunneling probability. We can acquire essential insights into this novel material system and its promise for future TFETs by analyzing the electrical characteristics of the C3N/Ga2O3 vdWHs.