Electrochemical Construction of Edge‐Contacted Metal‐Semiconductor Junctions with Low Contact Barrier

Abstract 2D semiconductors, such as MoS₂ have emerged as promising ultrathin channel materials for the further scaling of field‐effect transistors (FETs). However, the contact barrier at the metal‐2D semiconductor junctions still significantly limits the device's performance. By extending the application of electrochemical deposition in 2D electronics, a distinct approach is developed for constructing metal‐2D semiconductor junctions in an edge‐contacted configuration through the edge‐guided electrodeposition of varied metals. Both high‐resolution microscopic imaging and electrical transport measurements confirm the successful creation of high‐quality Pd‐2D MoS₂ junctions in desired geometry by combining electrodeposition with lithographic patterning. FETs are fabricated on the obtained Pd‐2D MoS₂ junctions and it is confirmed that these junctions exhibit a reduced contact barrier of ≈20 meV and extremely low contact resistance of 290 Ω µm and thus increase the averaged mobility of MoS₂ FETs to ≈108 cm² V ⁻¹ s⁻¹. This approach paves a new way for the construction of metal‐semiconductor junctions and also demonstrates the great potential of the electrochemical deposition technique in 2D electronics.