Quaternary NAND Logic and Complementary Ternary Inverter with p‐MoTe₂/n‐MoS₂ Heterostack Channel Transistors

Abstract

Applications of 2D semiconductors have been extensively studied, much oriented to various electron devices. Recently, multivalue field-effect transistors (FETs) are also included among 2D-based electron device studies in consideration that multivalue FETs may resolve power consumption issues in future integrated circuits. Several n-channel devices are thus reported along with a few p-channel devices, while studies to achieve both n-and p-channel multivalue FETs are hardly found. Here, both n-and p-channel multivalue FETs are fabricated using p-MoTe 2 /n-MoS 2 heterostack channel architecture, where either p-or n-channel ternary value FET is reproducible by switching the stacking order of p-and n-channel layer. The main ternary value mechanism originates from resonant tunneling type injection and channel inversion, which take place during device operation. For a state-of-the-art device application in 2D electronics, a quaternary NAND logic circuit is for the first time demonstrated by integrating two ternary n-channel FETs, and a complementary ternary inverter is also fabricated by integrating multivalue p-channel and plain n-channel FET.

Structure modulation of two-dimensional transition metal chalcogenides: recent advances in methodology, mechanism and applications

“…Thermal emission and tunnelling processes are operated by different V gs regions, taking advantage of different SBHs of heterointerfaces. 397–399 Gate-operated band alignments of p–n or n ++ –n junctions (n ++ , heavy n-type doping) exhibit distinct carrier injecting behaviours, i.e. , tunnelling and thermionic carriers, from one region to the other, consequently generating different carrier transfer characteristics.…”

Recent progress in functional two-dimensional photovoltaic photodetectors and related emerging applications

“…10d). 198 The inverter had a ternary value property due to the resonant tunneling type injection (from n-MoS 2 to p-MoTe 2 channels) and channel reversal. Therefore, the transfer characteristics of the heterostack field-effect transistors displayed ternary value I sd behavior: two ON states and OFF state (high ON: V sd = 1 V, intermediate ON: V sd = 0.1 V, and OFF: gate leakage) along with I sd dip depending on V g (Fig.…”

2D semiconductors for specific electronic applications: from device to system

“…The cascaded devices can be created for reconfigurable complex logic function circuits that facilitate the application of secure encryption. vdW heterojunctions of 2D semiconductors exhibit anti-bipolarity 88 , negative differential resistance 89 , or resonant tunnelling 90 depending on the band combinations, thus permitting the construction of novel multivalued logic calculations 91 . For example, the band alignment of heterojunctions composed of MoS 2 and BP can shift from type-I to type-II and type-III under effective gate control 92 .…”