Control of polarity in multilayer MoTe2 field-effect transistors by channel thickness

Published

November 9, 2018

Author(s)

Albert Davydov, Mona Zaghloul, Sergiy Krylyuk, Ratan K. Debnath, Asha Rani, Kyle J. DiCamillo, Payam Taheri

Abstract

In this study, electronic properties of field-effect transistors (FETs) fabricated from exfoliated MoTe2 single crystals are investigated as a function of channel thickness. The conductivity type in FETs gradually changes from n-type for thick MoTe2 layers (above 65 nm) to ambipolar behavior for intermediate MoTe2 thickness (between 60 and 15 nm) to p-type for thin layers (below 10 nm). The n- type behavior in quasi-bulk MoTe2 is attributed to doping with chlorine atoms from the TeCl4 transport agent used for the chemical vapor transport (CVT) growth of MoTe2. The change in polarity sign with decreasing channel thickness may be associated with increasing role of surface states in ultra-thin layers, which in turn influence carrier concentration and dynamics in the channel due to modulation of Schottky barrier height and band-bending at the metal/semiconductor interface.

Citation

Proceedings of SPIE

Volume

10725

Pub Type

Journals

Keywords

2D materials, MoTe2, FET

Citation

Davydov, A. , Zaghloul, M. , Krylyuk, S. , Debnath, R. , Rani, A. , DiCamillo, K. and Taheri, P. (2018), Control of polarity in multilayer MoTe2 field-effect transistors by channel thickness, Proceedings of SPIE (Accessed January 15, 2025)