Superconductor-semiconductor-superconductor lateral heterojunction diodes based on MSi2 N4 (M = Ta, Mo, W) monolayers

Heterojunctions of two-dimensional (2D) materials have generated substantial research interest due to their diverse and novel properties. In this study, we propose a class of superconductor-semiconductor-superconductor (SSS) lateral heterojunction diodes based on MSi2N4 (M = Ta,Mo, W) monolayers. Using the ab initio method, we simulate the time- and angle-resolved photoelectron spectroscopy (Tr-ARPES) for all MSi2N4 monolayers and, importantly, reveal the one-band and two-gap s-wave superconductivities in TaSi2N4. Furthermore, these SSS diodes exhibit a significant and tunable negative differential resistance (NDR) effect. Our findings suggest that MSi2N4 monolayers are promising platforms for studying superconducting materials and NDR-based nanodevices, further broadening the potential applications of the MA2Z4 family of materials in nanoelectronics.