Gate-voltage-induced reversible electrical phase transitions in Mo0.67W0.33Se2 devices. Issue 44 (1st November 2022)

• Record Type: Journal Article
• Authors: Kim, Min-Sik; Choi, Dong-Hwan; Lee, In-Ho; Kim, Wu-Sin; Kwon, Duhyuk; Bae, Myung-Ho; Kim, Ju-Jin
• Is Part Of: Nanoscale. Volume 14:Issue 44(2022)
• Page Start: 16611
• Page End: 16617
• Publication Date: 2022-11-01
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/d2nr04311d
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : Mo0.67 W0.33 Se2 devices show gate-voltage-induced electrical phase transitions. Abstract : Tunable electrical phase transitions based on the structural and quantum-state phase transitions in two-dimensional transition-metal dichalcogenides have attracted attention in both semiconducting electronics and quantum electronics applications. Here, we report gate-voltage-induced reversible electrical phase transitions in Mo0.67 W0.33 Se2 (MoWSe) field-effect transistors prepared on SiO2 /Si substrates. In gate-induced depletion regions of the 2H phase, an electrical current resumes flow at 150 K < T < 200 K with decreasing T irrespective of the layer number ( n ) for MoWSe when n < 20. The newly appearing electron-doped-type conducting channel again enters the 2H-phase region when the back-gate voltage increases, accompanied by the negative differential transconductance for four-layer and monolayer devices or by a deflection point in the transfer curves for a multilayer device. The thermal activation energies of the new conducting and 2H-phase branches differ by one order of magnitude at the same gate voltage for both the four-layer and monolayer cases, indicating that the electrical band at the Fermi level was modified. The hysteresis measurements for the gate voltage were performed with a five-layer device, which confirms the reversible electrical transition behavior. The possible origins of the nucleated conducting phase in the depletion region of the 2H phase of MoWSe are discussed.