Unipolar p-type monolayer WSe_(2) field-effect transistors with high current density and low contact resistance enabled by van der Waals contacts  

作　　者：Miaomiao Li Xinyu Zhang Zimei Zhang Gang Peng Zhihong Zhu Jia Li Shiqiao Qin Mengjian Zhu 

机构地区：[1]College of Advanced Interdisciplinary Studies & Hunan Provincial Key Laboratory of Novel Nano-optoelectronic Information Materials and Devices, National University of Defense Technology, Changsha, 410073, China [2]Nanhu Laser Laboratory, National University of Defense Technology, Changsha, 410073, China [3]Hunan Key Laboratory of Two-Dimensional Materials and State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, China [4]College of Science & Hunan Key Laboratory of Extreme Matter and Applications, National University of Defense Technology, Changsha, 410073, China

出　　处：《Nano Research》2024年第11期10162-10169,共8页纳米研究（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(No.12174444);M.Zhu acknowledges the fruitful discussion with Dr.Jinbao Jiang at National University of Defense Technology.

摘　　要：High-performance field-effect transistors (FETs) based on atomically thin two-dimensional (2D) semiconductors have demonstrated great promise in post-Moore integrated circuits. However, unipolar p-type 2D semiconductor transistors yet remain challenging and suffer from low saturation current density (less than 10 µA·µm^(−1)) and high contact resistance (larger than 100 kΩ·µm), mainly limited by the Schottky barrier induced by the mismatch of the work-functions and the Fermi level pinning at the metal contact interfaces. Here, we overcome these two obstacles through van der Waals (vdW) integration of high work-function metal palladium (Pd) as the contacts onto monolayer WSe2 grown by chemical vapor deposition (CVD) method. We demonstrate unipolar p-type monolayer WSe2 FETs with superior device performance: room temperature on-state current density exceeding 100 µA·µm^(−1), contact resistance of 12 kΩ·µm, on/off ratio over 107, and field-effect hole mobility of ~ 103 cm2·V^(−1)·s^(−1). Electrical transport measurements reveal that the Fermi level pinning effect is completely effectively eliminated in monolayer WSe2 with vdW Pd contacts, leading to a Schottky barrier-free Ohmic contact at the metal-semiconductor junctions. Combining the advantages of large-scale vdW contact strategy and CVD growth, our results pave the way for wafer-scale fabrication of complementary-metal-oxide-semiconductor (CMOS) logic circuits based on atomically thin 2D semiconductors.

关 键 词：two-dimensional(2D)field-effect transistors(FETs) monolayer WSe2 van der Waals(vdW)contact on-state current hole mobility 

分 类 号：TN32[电子电信—物理电子学]