International Journal of Physics | Vol. 12, No. 10, October 2021 | pp. 73–80
DOI: 10.46882/2021/IJP/000138
Research Article
Title: Optical Properties and Exciton Dynamics of Monolayer Tungsten Diselenide on Silicon Oxide Slot Waveguides
Names of Authors: Y. S. Kim¹, T. H. Nguyen²
Authors’ Affiliations:
¹ Department of Physics and Astronomy, Seoul National University, Seoul, South Korea
² Department of Physics, Vietnam National University, Hanoi, Vietnam
Abstract: Layered transition metal dichalcogenides have attracted significant industrial interest due to their strong light-matter couplings and potential for building chip-scale integrated optoelectronic platforms. This study characterises the optical properties and exciton dynamics of monolayer tungsten diselenide (WSe²) integrated onto silicon oxide slot waveguides. The monolayer flakes were synthesized via chemical vapor deposition and transferred onto the wave-guiding cores using an optimized dry-transfer technique. We performed micro-photoluminescence and angle-resolved reflectivity measurements under mechanical tensile strains from 0.0% to 1.6% at a room temperature of 300 K. The unstrained monolayer coupled to the slot waveguide area exhibits strong absorption lines, confirming efficient evanescent field capture. Applying a 1.0% tensile strain shifts the exciton resonance energy from 1.65 eV to 1.59 eV, yielding a strain tuning factor of 60.0 meV/% strain. Time-resolved photoluminescence spectroscopy revealed a shortened polariton decay lifetime, dropping from 16.5 ps down to 5.2 ps due to the dielectric slot Purcell effect. Our numerical models confirm that the tight localized electromagnetic field confinement within the slot increases the exciton-photon coupling rate by 35.0%. These findings demonstrate that slot-integrated strain architectures provide an effective path for tuning light-emitting states.
Keywords: Tungsten diselenide; slot waveguides; photoluminescence; exciton dynamics; tensile strain; integrated optics
Manuscript Timeline: Received: June 02, 2021; Revised: July 29, 2021; Accepted: August 25, 2021; Published: October 08, 2021
Citation: Kim, Y. S., & Nguyen, T. H. (2021). Optical Properties and Exciton Dynamics of Monolayer Tungsten Diselenide on Silicon Oxide Slot Waveguides. International Journal of Physics, 12(10), 73–80.
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