All-Inorganic Metal Oxide-Based p-n Heterojunction Ternary-State Transistors

Ternary logic has been proposed as a type of many-valued logic system to overcome the limitations of integration density and energy efficiency in the current complementary metal-oxide-semiconductor (CMOS) technology. In detail, p-n heterojunction transistors with ternary-state switching characteristics can implement ternary logic structures. However, most research on p-n heterojunction ternary-state transistors (TSTs) has focused on organic or 2D materials, which face significant challenges in meeting the demands of current CMOS technology. Nonetheless, due to the lack of suitable p-type oxide semiconductors, research on all-inorganic oxide-based TSTs has been limited. Herein, n-type TSTs are demonstrated through the formation of a p-n heterojunction inorganic oxide channel, comprising n-type indium gallium zinc oxide (IGZO) and p-type tellurium selenium oxide (TeSeO), which aligns with current CMOS technology requirements, including large-area fabrication and low annealing temperature. Due to the difference in resistance between IGZO and TeSeO, negative differential transconductance appears in a specific gate bias region of the switching characteristics. Specifically, the electron conduction path in the heterojunction channel varies with the amplitude of the gate bias, and we found that the construction of the heterojunction channel structure influences switching behavior. Finally, we successfully demonstrated all-inorganic oxide-based ternary logic applications using the n-type IGZO/TeSeO TSTs and p-type TeSeO transistors to validate practical implementation.