International Journal of Physics | Vol. 10, No. 11, November 2019 | pp. 81–88
DOI: 10.46882/2019/IJP/000115
Research Article
Title: Optical Properties and Exciton-Polariton Dynamics of Monolayer Molybdenum Disulfide on Dielectric Bragg Reflectors
Names of Authors: Y. S. Kim¹, C. M. Brauer²
Authors’ Affiliations:
¹ Department of Physics and Astronomy, Seoul National University, Seoul, South Korea
² Institut für Physik, Humboldt-Universität zu Berlin, Berlin, Germany
Abstract: Monolayer transition metal dichalcogenides have attracted significant interest due to their strong light-matter interactions and potential for nanoscale valleytronic devices. This study characterises the optical properties and exciton-polariton dynamics of monolayer molybdenum disulfide (MoS²) integrated onto dielectric silicon/silicon dioxide Bragg reflectors. The monolayer flakes were synthesized via chemical vapor deposition and transferred onto the nanostructured substrates using an optimized dry-transfer technique. We performed micro-photoluminescence and angle-resolved reflectivity measurements under mechanical tensile strains from 0.0% to 1.8% at a room temperature of 300 K. The unstrained monolayer coupled to the microcavity exhibits a strong Rabi splitting of 48.2 meV, confirming the transition into the strong light-matter coupling regime. Applying a 1.2% tensile strain shifts the exciton resonance energy from 1.85 eV to 1.78 eV, yielding a strain tuning factor of 58.3 meV/% strain. Time-resolved photoluminescence spectroscopy revealed a shortened polariton decay lifetime, dropping from 14.5 ps down to 4.2 ps due to the microcavity Purcell effect. Our numerical models confirm that the localized electromagnetic field confinement within the mirrors increases the exciton-photon coupling rate by 40.0%. These findings demonstrate that cavity-integrated strain engineering offers an effective route for controlling exciton-polariton states in thin-film optoelectronic architectures.
Keywords: Molybdenum disulfide; Bragg reflectors; photoluminescence; exciton-polariton; tensile strain; light-matter coupling
Manuscript Timeline: Received: July 12, 2019; Revised: September 04, 2019; Accepted: September 22, 2019; Published: November 12, 2019
Citation: Kim, Y. S., & Brauer, C. M. (2019). Optical Properties and Exciton-Polariton Dynamics of Monolayer Molybdenum Disulfide on Dielectric Bragg Reflectors. International Journal of Physics, 10(11), 81–88.
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