Abstract: Interfacial coupling, including subtle charge transfer effects, between a work-function-matched insulator substrate and a two-dimensional (2D) transition-metal disulfide semiconductor is an emerging tuning knob in tailoring the electrical properties of the latter. For example, it can effectively turn the originally n-type semiconductor into a p-type one, leading to opportunities for vertically integrated complementary field-effect transistors and novel p-n junctions. However, the electrical anisotropy in the charge-transferred p-type 2D semiconductor remained largely unknown, while the insulating substrate itself has been reported to often exhibit strong optical anisotropy. Here, taking MoS₂/CrOCl heterostructure as an example, we show that such a charge-transferred p-type semiconductor can indeed exhibit a pronounced twofold-symmetric anisotropic conductance, with a maximum anisotropy ratio up to 4-5 times at the same gate voltage. We further reveal the correlation between optical and electrical anisotropy in such hybrid systems. Our study thus identifies a new family of 2D in-plane anisotropic conductance in charge-transferred p-type 2D semiconductors, and offers insights for related future nano-electronic device design.

Key words: 2D semiconductor, Electrical anisotropy, Field effect transistor