Tunable Intermediate-Logic Ternary Circuits based on MoSe2-WSe2 Heterojunction

Abstract

Van der Waals (vdW) heterojunctions, which consist of p-type and n-type semiconductors, have provided new features for transition metal dichalcogenides (TMDs). In this work, a negative differential transconductance (NDT) transistor based on a MoSe2-WSe2 heterojunction (MoSe2-WSe2 H-TR) is proposed. The MoSe2-WSe2 H-TR provides desirable device characteristics for ternary circuit operation with a switching behavior of off-state / p-type turn-on / NDT region / p-type turn-on. As a result, a 100% output voltage (VOUT) swing inverter can be achieved in a ternary inverter, which consists of the proposed MoSe2-WSe2 vdW-H-TR and a MoS2 floating-gate transistor. Furthermore, a tunable intermediate-logic ternary circuit operation is demonstrated by controlling the threshold voltage (VTH) in a pull-down n-type MoS2 floating-gate transistor. We also investigated that a light-induced operation on the MoSe2-WSe2 vdW-H-TR offers control of the VOUT amplitude at the intermediate-logic state. Based on the proposed MoSe2-WSe2 vdW-H-TR, this work suggests a strategy to obtain a tunable ternary circuit, thus providing a new concept of heterojunction electronics using layered TMDs.

High-performance multivalued logic circuits based on optically tunable antiambipolar transistors

“…In a similar manner, optically tunable MVL has been reported in a-6T/PTCDI-C8 and MoSe 2 / WSe 2 systems. 29,35 In a-6T/PTCDI-C8 system, the photoresponse of a-6T was superior to that of PTCDI-C8 under both UV and visible light irradiation, and this impeded effective light tunability. In addition, visible and UV light was found to degrade the V OUT level of logic 1 and logic 1/2 state, respectively.…”

“…However, no effective controllability in the logic state positions and widths were observed. 35 The combination of C8-BTBT and PhC 2 -BQQDI provides an advantage in this regard. We can separately activate C8-BTBT or PhC 2 -BQQDI using a UV or visible light signal and precisely control the width, position and V OUT level of the inverter logic states.…”

“…[15][16][17][18][19] A wide variety of twodimensional (2D) materials and organic semiconductors have already been investigated with a view to further improve the device performance of the AATs and MVLs. [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35] In most of the studies transition metal dichalcogenides (TMDCs) such as molybdenum disulfide (MoS 2 ), tungsten diselenide (WSe 2 ) and tin diselenide (SnSe 2 ) were employed owing to their advantages of dangling bond free surface properties, superior electronic performance metrics and high stability under mechanical stress. [20][21][22][23][24][25][30][31][32][33][34][35][36][37] However, TMDCs have a fatal disadvantage as regards to their film processing method.…”

“…[20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35] In most of the studies transition metal dichalcogenides (TMDCs) such as molybdenum disulfide (MoS 2 ), tungsten diselenide (WSe 2 ) and tin diselenide (SnSe 2 ) were employed owing to their advantages of dangling bond free surface properties, superior electronic performance metrics and high stability under mechanical stress. [20][21][22][23][24][25][30][31][32][33][34][35][36][37] However, TMDCs have a fatal disadvantage as regards to their film processing method. Most of the TMDC films and the devices are fabricated through mechanical exfoliation technique using adhesive tapes.…”