Focused helium-ion beam irradiation effects on electrical transport properties of few-layer WSe2: enabling nanoscale direct write homo-junctions.
Atomically thin transition metal dichalcogenides (TMDs) are currently receiving significant attention due to their promising opto-electronic properties. Tuning optical and electrical properties of mono and few-layer TMDs, such as tungsten diselenide (WSe2), by controlling the defects, is an intriguing opportunity to synthesize next generation two dimensional material opto-electronic devices. Here, we report the effects of focused helium ion beam irradiation on the structural, optical and electrical properties of few-layer WSe2, via high resolution scanning transmission electron microscopy, Raman spectroscopy, and electrical transport measurements. By controlling the ion irradiation dose, we selectively introduce precise defects in few-layer WSe2 thereby locally tuning the resistivity and transport properties of the material. Hole transport in the few layer WSe2 is degraded more severely relative to electron transport after helium ion irradiation. Furthermore, by selectively exposing material with the ion beam, we demonstrate a simple yet highly tunable method to create lateral homo-junctions in few layer WSe2 flakes, which constitutes an important advance towards two dimensional opto-electronic devices.
Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA.
Michael G
MG
Stanford
Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA.
Pushpa Raj
PR
Pudasaini
Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
Alex
A
Belianinov
Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA.
Nicholas
N
Cross
Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA.
Joo Hyon
JH
Noh
Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA.
Michael R
MR
Koehler
Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA.|Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
David G
DG
Mandrus
Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA.|Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
Gerd
G
Duscher
Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
Adam J
AJ
Rondinone
Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
Ilia N
IN
Ivanov
Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
T Zac
TZ
Ward
Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA.|Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
Philip D
PD
Rack