Two-Dimensional 2H-TaS 2 Contact for Fermi-Level Pinning-Free P-Type WSe 2 Field-Effect Transistors

作者：Delong Cui, Shuwen Shen, Wenxuan Wu, Weiao Chen, Xueting Zhou, Jinkun Han, Xiaofei Yue, Jiahao Li, Ran Liu, Laigui Hu, Chunxiao Cong, Zhi‐Jun Qiu · 发表于：ACS Applied Materials & Interfaces · 年份：2025 · DOI：10.1021/acsami.5c12502 · 被引用次数：6 · 研究领域：2D Materials and Applications、MXene and MAX Phase Materials、Graphene research and applications

Two-dimensional (2D) transition metal dichalcogenides (TMDs), represented by WSe 2, have exhibited considerable promise in complementary metal-oxide-semiconductor and optoelectronic device applications due to their tunable bandgap and the prospect of compatibility with conventional silicon-based processes. However, the precise control of p-type transport characteristics in 2D TMDs has been challenging due to the Fermi-level pinning effect at the interface with evaporated metal electrodes, resulting in most TMDs exhibiting a single n-type conductivity and significantly impeding the achievement of p-type and n-type contacts by using homogeneous materials. Here, we present Fermi-level pinning-free WSe 2 field-effect transistors via 2D van der Waals 2H-TaS 2 contacts, establishing an exceptionally clean and atomically flat interface between the WSe 2 semiconductor and the 2H-TaS 2 metal. Such contacts enable the Schottky barrier height to closely match the work function of the 2H-TaS 2 electrodes, as evidenced by a pinning factor of 0.95, conforming to the Schottky–Mott rule. The integration of TaS2 as contacts in WSe 2 field-effect transistors results in p-type polarity, predominantly driven by hole transport, without the need for external doping, demonstrating a hole mobility of 23.74 cm 2 V –1 s –1 and an on/off current ratio of 1 × 10 7 . Our findings further reveal that the p-type polarity achieved through this interface engineering strategy exhibits robustness, regardless o...