Superconducting Layered NbSe₂ Electrodes for Semiconductors

Semiconductor/superconductor hybrid architecture is essential for various applications in quantum and nanoelectronic devices, such as a platform for non-Abelian quasiparticle manipulation (braiding Majorana fermion), Josephson junction, and cryoelectronics. Design and physical implementation of semiconductor/superconductor hybrid architecture is significantly affected by interfacial properties at the junction between the semiconductor and the superconductor, which are processing-dependent. To overcome the processing-dependent property issue, layered metallic materials have been considered as constituents, immune to interface and surface states altering the interfacial properties because high-quality layered materials do not have surface dangling bonds where the processing-dependent interfacial properties are induced. There have been reports of the semiconductor/layered metallic heterostructures exhibiting contact characteristics fit to Schottky-Mott physics. However, we have found that there should be materials-dependent characteristics not fit to Schottky-Mott physics.
Here, we present theoretical modeling and experimental observations of electrical behaviors of several hybrid architectures composed of narrow (Si) and wide band gap (ZnO) semiconductors and superconducting NbSe₂. Density function theory (DFT) calculations and interfacial charge analyses showed charge transfer-induced barrier height change and Fermi-level pinning/depinning. The theoretical modeling was validated in the hybrid architectures prepared by heterostructure formation via direct growth and materials stacking.