Angle-Dependent Conductivity in MoS₂ Field-Effect Transistors with Bi Contacts

The directional dependence of single crystalline molybdenum disulfide (MoS₂) critically influences its electronic transport properties. Recent advances in contact engineering have enabled ultralow contact resistance in MoS₂ field-effect transistors (FETs) using semi-metal bismuth (Bi) contacts. In this work, we systematically investigate the angle-dependent conductivity of Bi-contacted MoS₂ FETs by varying the relative orientation between the electrodes and the MoS₂ lattice. The conductivity exhibits a continuous angular dependence, reaching a maximum at 0° and minimum at 30°, with nearly a twofold enhancement at the optimal alignment. These results demonstrate that precise control of contact orientation is essential for realizing high-performance two-dimensional devices and provide valuable guidelines for designing next-generation heterogeneous integrated circuits with enhanced energy efficiency and computational speed.