TY - JOUR

T1 - Patterning GaSe by High-Powered Laser Beams

AU - Cheshev, Dmitry

AU - Rodriguez, Raul

AU - Matkovic, Aleksandar

AU - Ruban, Alexey

AU - Chen, Jin-Ju

AU - Sheremet, Evgeniya

N1 - Publisher Copyright: Copyright © 2020 American Chemical Society.

PY - 2020/4/24

Y1 - 2020/4/24

N2 - We report the high-powered laser modification ofthe chemical, physical, and structural properties of the twodimensional(2D) van der Waals material GaSe. Our results showthat contrary to expectations and previous reports, GaSe at theperiphery of a high-power laser beam does not entirely decomposeinto Se and Ga2O3. In contrast, we find unexpectedly that theRaman signal from GaSe gets amplified around regions where itwas not expected to exist. Atomic force microscopy (AFM),dielectric force microscopy (DFM), scanning electron microscopy(SEM), and energy-dispersive X-ray spectroscopy (EDX) resultsshow that laser irradiation induces the formation of nanoparticles.Our analyses demonstrate that, except for a fraction of Ga2Se3, these nanoparticles still belong to the GaSe phase but possessdifferent electrical and optical properties. These changes are evidenced in the increased Raman intensity attributed to the nearresonanceconditions with the Raman excitation laser. The elemental analysis of nanoparticles shows that the relative seleniumcontent increased to as much as 70% from a 50:50 value in stoichiometric GaSe. This elemental change is related to the formation ofthe Ga2Se3 phase identified by Raman spectroscopy at some locations near the edge. Further, we exploit the localized high-powerlaser processing of GaSe to induce the formation of Ag−GaSe nanostructures by exposure to a solution of AgNO3. The selectivereaction of AgNO3 with laser-irradiated GaSe gives rise to composite nanostructures that display photocatalytic activity originallyabsent in the pristine 2D material. The photocatalytic activity was investigated by the transformation of 4-nitrobenzenethiol to itsamino and dimer forms detected in situ by Raman spectroscopy. This work improves the understanding of light−matter interactionin layered systems, offering an approach to the formation of laser-induced composites with added functionality.

AB - We report the high-powered laser modification ofthe chemical, physical, and structural properties of the twodimensional(2D) van der Waals material GaSe. Our results showthat contrary to expectations and previous reports, GaSe at theperiphery of a high-power laser beam does not entirely decomposeinto Se and Ga2O3. In contrast, we find unexpectedly that theRaman signal from GaSe gets amplified around regions where itwas not expected to exist. Atomic force microscopy (AFM),dielectric force microscopy (DFM), scanning electron microscopy(SEM), and energy-dispersive X-ray spectroscopy (EDX) resultsshow that laser irradiation induces the formation of nanoparticles.Our analyses demonstrate that, except for a fraction of Ga2Se3, these nanoparticles still belong to the GaSe phase but possessdifferent electrical and optical properties. These changes are evidenced in the increased Raman intensity attributed to the nearresonanceconditions with the Raman excitation laser. The elemental analysis of nanoparticles shows that the relative seleniumcontent increased to as much as 70% from a 50:50 value in stoichiometric GaSe. This elemental change is related to the formation ofthe Ga2Se3 phase identified by Raman spectroscopy at some locations near the edge. Further, we exploit the localized high-powerlaser processing of GaSe to induce the formation of Ag−GaSe nanostructures by exposure to a solution of AgNO3. The selectivereaction of AgNO3 with laser-irradiated GaSe gives rise to composite nanostructures that display photocatalytic activity originallyabsent in the pristine 2D material. The photocatalytic activity was investigated by the transformation of 4-nitrobenzenethiol to itsamino and dimer forms detected in situ by Raman spectroscopy. This work improves the understanding of light−matter interactionin layered systems, offering an approach to the formation of laser-induced composites with added functionality.

UR - http://www.scopus.com/inward/record.url?scp=85084232595&partnerID=8YFLogxK

U2 - 10.1021/acsomega.0c01079

DO - 10.1021/acsomega.0c01079

M3 - Article

VL - 5.2020

SP - 10183

EP - 10190

JO - ACS omega

JF - ACS omega

SN - 2470-1343

IS - 17

M1 - 5

ER -