Sb₂Te₃/MoS₂ Van der Waals Junctions with High Thermal Stability and Low Contact Resistance

Abstract

Two‐dimensional transition metal dichalcogenides (TMDCs) demonstrate great potential in nanoelectronics devices owing to their high carrier mobility in the atomically thin channel regime. However, high contact resistance between source/drain electrodes and TMDC channels hinders the TMDCs applications in the very‐large‐scale integration (VLSI) field. Here, this work reports atomically aligned van der Waals (vdW) junction fabrications through thermal‐induced crystallization of layered Sb2Te3 electrodes on monolayer MoS2 using VLSI‐compatible physical vapor deposition and annealing processes. Due to Fermi‐level unpinning with a small band offset between Sb2Te3 and MoS2 and small density of state of Sb2Te3, better device performance is demonstrated on MoS2 MOSFETs with Sb2Te3/W contact than that of Sb/W contact. Moreover, the ideal vdW junctions are found to demonstrate extreme high‐thermal robustness. No intermixing at the Sb2Te3/MoS2 interface or crystallinity degradation of Sb2Te3 is observed after 450 °C annealing, leading to higher thermal stability than its Sb counterpart. Sb2Te3 is a promising candidate as an n‐type contact material for TMDC‐based devices such as MoS2, MoSe2, and WS2 in future VLSI electronics and various other applications.

Emerging Schemes for Advancing 2D Material Photoconductive-Type Photodetectors

“…Figure 5d presents the spectral photoresponse of the pristine MoS2 and AgNDs/MoS2 photodetectors. It is clearly determined that the responsivity of the AgNDs/MoS2 photodetector is superior to that of the counterpart MoS2 Thus far, in addition to topological insulators, many other metallic/semimetallic 2DLMs, such as graphene [130,131], graphite [132], reduced graphene oxide [133], 1T -WS 2 [134], TaSe 2 [135,136], ZrTe 2 [137], Sb 2 Te 3 [138], etc., have been validated as highly competitive self-passivated electrode building blocks. These 2DLMs have different work functions, providing rich choices for device design.…”

Electrical properties and band alignments of Sb2Te3/Si heterojunctions, low-barrier Sb2Te3/n-Si and high-barrier Sb2Te3/p-Si junctions

“…In a previous study, we demonstrated the vdW stacking of antimony telluride (Sb 2 Te 3 ) on molybdenum disulfide (MoS 2 ), 16) and showed a substantial enhancement in the device performance of monolayer MoS 2 n-type FETs with Sb 2 Te 3 source/drain contacts, which was resulted from a significant reduction of contact resistance. This result suggests that the conduction band edges of Sb 2 Te 3 and MoS 2 are closely aligned.…”