Complementary Logic Driven by Dielectrophoretic Assembly of 2D Semiconductors

Abstract

2D semiconductors have emerged as promising channel materials for complementary logic circuits in future electronics. Efforts to scale them beyond a few-device-level demonstrations toward practical circuit fabrication have primarily relied on chemical vapor deposition or solution-based exfoliation of bulk crystals into 2D nanosheets. While the latter offers a facile and cost-effective approach for producing 2D semiconductors, scalable fabrication and integration of complementary doping schemes to produce complex integrated circuits has been challenging. Here, a scalable, parallel fabrication strategy is developed to realize 2D semiconductor-based complementary logic gates through electric-field-driven deterministic assembly of nanosheet dispersions. Arrays of n-type and p-type semiconducting channels are formed by selectively assembling electrochemically exfoliated MoS2 and WSe2 nanosheets between source and drain electrodes using alternating current dielectrophoresis (AC-DEP), followed by solution-based chemical treatment to passivate chalcogen vacancies. Under optimal AC-DEP processing conditions, the MoS2 and WSe2 field-effect transistors (FETs) exhibit average field-effect mobilities of 4.3 and 3.0 cm2 V-1 s-1, respectively, and average on/off current ratios exceeding 104. The capability of the approach to precisely position n-channel and p-channel FETs enables scalable and parallel fabrication of diverse complementary logic gates-such as NOT, NAND, and NOR-and static random access memory.