Microscopic Origin of Inhomogeneous Transport in Four-Terminal Tellurene Devices

Published

December 22, 2020

Author(s)

Benjamin Kupp, Gang Qiu, Yixiu Wang, Clayton Caspeer, Thomas Mitchell (Mitch) Wallis, Joanna Atkin, Wenzhuo Wu, Peide Ye, Pavel Kabos, Samuel Berweger

Abstract

Tellurene—the 2D form of elemental tellurium—provides an attractive alternative to conventional 2D semiconductors due to its high bipolar mobilities, facile solution processing, and the possibility of dopant intercalation into its 1D van der Waals lattice. Here, we study the microscopic origin of transport anisotropy in lithographically defined four-terminal tellurene devices using spatially resolved near-field scanning microwave microscopy (SMM). Our conductivity- and carrier type-sensitive SMM imaging reveals that the overall p-type transport measured between adjacent and opposite terminals originates from strong p-type character at the device edges. Despite using an atomic layer deposition-grown conformal overcoat that n-dopes the device interior, we observe only weak n-type transport along the main device channel at positive backgate voltages. This weak n-type transport along the device channel is shown to arise from local p-doping within a few micrometers of the electrodes, which produces a transport barrier from the n-type interior to the electrodes. These results reveal how the backgate-dependent conduction anisotropy could be leveraged to weigh different inputs for non-von Neumann architectures.

Citation

Applied Physics Letters

Volume

117

Pub Type

Journals

Download Paper

https://doi.org/10.1063/5.0025955

Local Download

Keywords

Scanning Probe, Near-field

Citation

Kupp, B. , Qiu, G. , Wang, Y. , Caspeer, C. , Wallis, T. , Atkin, J. , Wu, W. , Ye, P. , Kabos, P. and Berweger, S. (2020), Microscopic Origin of Inhomogeneous Transport in Four-Terminal Tellurene Devices, Applied Physics Letters, [online], https://doi.org/10.1063/5.0025955, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=930776 (Accessed April 19, 2024)