TY - JOUR
T1 - Precision Modification of Monolayer Transition Metal Dichalcogenides via Environmental E-Beam Patterning
AU - Selhorst, Ryan
AU - Yu, Zhuohang
AU - Moore, David
AU - Jiang, Jie
AU - Susner, Michael A.
AU - Glavin, Nicholas R.
AU - Pachter, Ruth
AU - Terrones, Mauricio
AU - Maruyama, Benji
AU - Rao, Rahul
N1 - Funding Information:
R.S., J.J. R.P, B.M., M.A.S., and R.R. acknowledge funding from the Air Force Office of Scientific Research under grant number 19RTXCOR052. N.G. and D.M. acknowledge support from Air Force Office of Scientific Research under grant number FA9550-20RXCOR057.
Publisher Copyright:
© 2023 American Chemical Society.
PY - 2023/2/14
Y1 - 2023/2/14
N2 - Layered Transition Metal Dichalcogenides (TMDs) are an important class of materials that exhibit a wide variety of optoelectronic properties. The ability to spatially tailor their expansive property-space (e.g., conduction behavior, optical emission, surface interactions) is of special interest for applications including, but not limited to, sensing, bioelectronics, and spintronics/valleytronics. Current methods of property modulation focus on the modification of the basal surfaces and edge sites of the TMDs by the introduction of defects, functionalization with organic or inorganic moieties, alloying, heterostructure formation, and phase engineering. A majority of these methods lack the resolution for the development of next-generation nanoscale devices or are limited in the types of functionalities useful for efficient TMD property modification. In this study, we utilize electron-beam patterning on monolayer TMDs (MoSe2, WSe2 and MoS2) in the presence of a pressure-controlled atmosphere of water vapor within an environmental scanning electron microscope (ESEM). A series of parametric studies show local optical and electronic property modification depending on acceleration voltage, beam current, pressure, and electron dose. The ultimate pattern resolution achieved is 67 ± 9 nm. Raman and photoluminescence spectroscopies coupled with Kelvin Probe Force Microscopy reveal electron dose-dependent p-doping in the patterned regions, which we attribute to functionalization from the products of water vapor radiolysis (oxygen and hydroxyl groups). The modulation of the work function through patterning matches well with Density Functional Theory modeling. Finally, post-functionalization of the patterned areas with an organic fluorophore demonstrates a robust method to achieve nanoscale functionalization with high fidelity.
AB - Layered Transition Metal Dichalcogenides (TMDs) are an important class of materials that exhibit a wide variety of optoelectronic properties. The ability to spatially tailor their expansive property-space (e.g., conduction behavior, optical emission, surface interactions) is of special interest for applications including, but not limited to, sensing, bioelectronics, and spintronics/valleytronics. Current methods of property modulation focus on the modification of the basal surfaces and edge sites of the TMDs by the introduction of defects, functionalization with organic or inorganic moieties, alloying, heterostructure formation, and phase engineering. A majority of these methods lack the resolution for the development of next-generation nanoscale devices or are limited in the types of functionalities useful for efficient TMD property modification. In this study, we utilize electron-beam patterning on monolayer TMDs (MoSe2, WSe2 and MoS2) in the presence of a pressure-controlled atmosphere of water vapor within an environmental scanning electron microscope (ESEM). A series of parametric studies show local optical and electronic property modification depending on acceleration voltage, beam current, pressure, and electron dose. The ultimate pattern resolution achieved is 67 ± 9 nm. Raman and photoluminescence spectroscopies coupled with Kelvin Probe Force Microscopy reveal electron dose-dependent p-doping in the patterned regions, which we attribute to functionalization from the products of water vapor radiolysis (oxygen and hydroxyl groups). The modulation of the work function through patterning matches well with Density Functional Theory modeling. Finally, post-functionalization of the patterned areas with an organic fluorophore demonstrates a robust method to achieve nanoscale functionalization with high fidelity.
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U2 - 10.1021/acsnano.2c11503
DO - 10.1021/acsnano.2c11503
M3 - Article
C2 - 36689725
AN - SCOPUS:85146886307
SN - 1936-0851
VL - 17
SP - 2958
EP - 2967
JO - ACS nano
JF - ACS nano
IS - 3
ER -