Electronic Tuning in WSe<sub>2</sub>/Au via van der Waals Interface Twisting and Intercalation
Qilong Wu, Meysam Bagheri Tagani, Lijie Zhang, Lijie Zhang, Jing Wang, Yu Xia, Li Zhang, Li Zhang, Sheng‐Yi Xie, Yuan Tian, Long‐Jing Yin, Wen Zhang, А. Н. Руденко, Andrew T. S. Wee, Ping Kwan Johnny Wong, Zhihui Qin
Abstract
The transition metal dichalcogenide (TMD)–metal interfaces constitute an active part of TMD-based electronic devices with optimized performances. Despite their decisive role, current strategies for nanoscale electronic tuning remain limited. Here, we demonstrate electronic tuning in the WSe2/Au interface by twist engineering, capable of modulating the WSe2 carrier doping from an intrinsic p-type to n-type. Scanning tunneling microscope/spectroscopy gives direct evidence of enhanced interfacial interaction induced doping in WSe2 as the twist angle with respect to the topmost (100) lattice of gold changing from 15 to 0°. Taking advantage of the strong coupling interface achieved this way, we have moved a step further to realize an n–p–n-type WSe2 homojunction. The intrinsic doping of WSe2 can be recovered by germanium intercalation. Density functional theory calculations confirm that twist angle and intercalation-dependent charge transfer related doping are involved in our observations. Our work offers ways for electronically tuning the metal–2D semiconductor interface.