International Journal of Physics | Vol. 8, No. 12, December 2017 | pp. 89–96
DOI: 10.46882/2017/IJP/000092
Research Article
Title: Optical Properties and Exciton Dynamics of Monolayer Molybdenum Diselenide on Silicon Nitride Waveguides
Names of Authors: Y. S. Kim¹, T. H. Nguyen²
Authors’ Affiliations: ¹Department of Physics and Astronomy, Seoul National University, Seoul, South Korea; ²Department of Physics, Vietnam National University, Hanoi, Vietnam
Abstract: Monolayer transition metal dichalcogenides have attracted significant interest due to their strong light-matter interactions and potential for integrated nanophotonic circuits. This study characterizes the optical properties and exciton dynamics of monolayer molybdenum diselenide (MoSe²) integrated onto silicon nitride wave-guiding structures. The monolayer flakes were synthesized via chemical vapor deposition and transferred onto the waveguides 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 evanescent field of the waveguide exhibits strong absorption lines, confirming efficient evanescent phase-coupling. Applying a 1.0% tensile strain shifts the exciton resonance energy from 1.55 eV to 1.49 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 Purcell effect. Our numerical models confirm that the localized electromagnetic field confinement within the silicon nitride core increases the exciton-photon coupling rate by 35.0%. These findings demonstrate that waveguide-integrated strain engineering offers an effective route for controlling exciton-polariton states in thin-film optoelectronic architectures.
Keywords: Molybdenum diselenide; silicon nitride; photoluminescence; exciton dynamics; tensile strain; integrated photonics
Manuscript Timeline: Received: August 18, 2017; Revised: October 10, 2017; Accepted: November 02, 2017; Published: December 15, 2017
Citation: Kim, Y. S., & Nguyen, T. H. (2017). Optical Properties and Exciton Dynamics of Monolayer Molybdenum Diselenide on Silicon Nitride Waveguides. International Journal of Physics, 8(12), 89–96.
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