Amorphous BN - Hexagonal MoTe2 Heterostructures for Improved Oxidation Resistance and Endurance of 2D Field Effect Transistors

Published

June 6, 2018

Author(s)

Benjamin Sirota, Nicholas Glavin, Sergiy Krylyuk, Albert Davydov, Andrey A. Voevodin

Abstract

Environmental and thermal stability of two-dimensional (2D) transition metal dichalcogenides (TMDs) remains a fundamental challenge towards enabling robust electronic devices. Few-layer 2H-MoTe2 with an amorphous boron nitride (a-BN) covering layer was synthesized as a heterojunction channel for back-gated field effect transistors (FET) and compared to uncovered MoTe2. A systematic approach was taken to understand the effects of heat treatment in air on the performance of FET devices. Atmospheric oxygen was shown to negatively affect uncoated MoTe2 devices while BN-covered FETs showed remarkable chemical and electronic characteristic stability. Uncapped MoTe2 FET devices, which were heated in air for one minute, showed a polarity switch from n- to p-type at 150 °C, while BN-MoTe2 devices switched only after heat treatment at 200 °C. Time-dependent experiments at 100 °C showed that uncapped MoTe2 samples exhibited the polarity switch after 15 min of heat treatment while the BN-capped device maintained its n-type conductivity. X-ray photoelectron spectroscopy (XPS) analysis suggests that substitution of oxygen for tellurium was the primary doping mechanism for the polarity switch. This work demonstrates the effectiveness of an a-BN capping layer in preserving few- layer MoTe2 material quality and controlling its conductivity type at elevated temperatures in an atmospheric environment.

Citation

Nature - Scientific Reports

Volume

8

Pub Type

Journals

Citation

Sirota, B. , Glavin, N. , Krylyuk, S. , Davydov, A. and Voevodin, A. (2018), Amorphous BN - Hexagonal MoTe2 Heterostructures for Improved Oxidation Resistance and Endurance of 2D Field Effect Transistors, Nature - Scientific Reports (Accessed May 31, 2023)