The Role of Electron-Electron Interaction in Charge Transport Calculations through Transition Metal Dichalcogenides Heterojunctions

2D materials have raised a lot of interest in the last decades, due to their novel and diverse properties, particularly for energy technology applications where materials such as molybdenum disulfide are known for their outstanding catalytic ability. While intensive research is devoted to 2D transition metal dichalcogenide (TMDCs) semiconductor characterization, comprehensive understanding of metal/semiconductor heterojunctions is still lacking especially for junctions containing 2D metallic monolayers other than graphene. Using wave-packet propagation, charge transport of two electrons through heterojunctions is simulated, in order to assess the influence of the electron-electron interaction on the charge transport efficiency. TMDCs with similar structure for both metal and semiconductor monolayers are used, leading to a high-quality metal contact. It is found that charge transport is more efficient in systems containing a chromium disulfide semiconductor monolayer compared to systems with MoS2 or tungsten disulfide. This trend in the efficiency is the same with and without electron-electron interaction, demonstrating the validity of the qualitative input provided by models that lack electron-electron interactions. Nevertheless, for all systems, the interaction increases charge transmission probability from the metal to the semiconductor, due to electronic repulsion that pushes one of the charge carriers forward across the interface.

Automated summary

2D materials, such as molybdenum disulfide, have attracted a lot of attention recently due to their unique properties, especially their catalytic ability for energy technology applications. However, there is still a lack of comprehensive understanding of metal/semiconductor heterojunctions containing 2D metallic monolayers other than graphene. This study simulates the charge transport through heterojunctions and finds that systems with a chromium disulfide semiconductor monolayer have more efficient charge transport compared to systems with MoS2 or tungsten disulfide. The electron-electron interaction increases the charge transmission probability from the metal to the semiconductor in all systems.