Angle-Dependent Carrier Transport at the Bi/MoS₂ Interface: Correlation Between Experimental Observations and Theoretical Analysis

Han-Chieh Lo^1,2*, Tilo H. Yang³, Ming-Hao Liu⁴, Yann-Wen Lan²

¹Graduate School of Advanced Technology, National Taiwan University, Taipei, Taiwan
²Department of Physics, National Taiwan Normal University, Taipei, Taiwan
³Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
⁴Department of Physics, National Cheng Kung University, Tainan, Taiwan

* Presenter:Han-Chieh Lo, email:d13k44017@g.ntu.edu.tw

The electrical transport properties of two-dimensional (2D) material-based heterostructures are highly sensitive to lattice alignment and interfacial coupling. In this work, we systematically investigate the angle-dependent conductivity and carrier mobility at the bismuth (Bi)–molybdenum disulfide (MoS₂) interface. By controlling the rotational alignment between the Bi contact and MoS₂ channel, both experimental measurements and theoretical simulations reveal significant modulation in transport characteristics. The conductivity exhibits a remarkable ~5.8× enhancement when the rotation angle decreases from 30° to 0°. These results indicate that precise control of interlayer twist angle can effectively tailor interfacial coupling strength and electron injection efficiency. Simulation results further demonstrate that the twist angle significantly influences carrier injection and the corresponding transmission distribution, with the 0° configuration yielding the highest transmission and the 30° configuration the lowest. These findings confirm that lattice-matching engineering provides an effective strategy for tuning interfacial coupling strength and electron injection efficiency, offering a promising route toward optimizing device performance in future heterogeneous integrated circuits to enhance both power efficiency and computational speed.

Keywords: Two-dimensional material, Contact engineering, Twist angle-dependent, Transition-metal dichalcogenides