International Journal of Physics | Vol. 5, No. 1, January 2014 | pp. 1–8
DOI: 10.46882/2014/IJP/000045
Research Article
Title: Optical Properties and Exciton Dynamics of Monolayer Molybdenum Disulfide on Flexible Substrates
Names of Authors: Y. S. Kim¹, J. L. Vigneron²
Authors’ Affiliations: ¹Department of Physics and Astronomy, Seoul National University, Seoul 08826, South Korea; ²Laboratoire de Physique du Solide, Facultés Universitaires Notre-Dame de la Paix, B-5000 Namur, Belgium
Abstract: Monolayer transition metal dichalcogenides have gained significant attention due to their direct bandgap properties and potential for flexible optoelectronic applications. This study characterizes the optical properties and exciton dynamics of monolayer molybdenum disulfide (MoS²) transferred onto flexible polyethylene terephthalate substrates. The monolayer flakes were synthesized via chemical vapor deposition and verified using micro-Raman spectroscopy. Photoluminescence measurements were performed under mechanical tensile strains varying from 0.0% to 2.0% at room temperature. The unstrained monolayer exhibits a strong photoluminescence peak at 1.85 eV, corresponding to the direct A-exciton transition. Applying a 1.5% tensile strain induces a systematic redshift in the exciton peak to 1.76 eV, yielding a strain gauge factor of 60.0 meV/% strain. Time-resolved photoluminescence spectroscopy revealed a multi-exponential exciton decay profile. The fast decay component, associated with defect-mediated non-radiative recombination, decreased from 18.5 ps to 11.2 ps under maximum strain conditions. This change indicates a strain-induced increase in defect capture cross-sections. Our calculations show that mechanical strain effectively tunes the spin-orbit splitting at the valence band extrema. These experimental findings offer valuable insights for engineering tunable light-emitting devices and flexible optical sensors.
Keywords: Molybdenum disulfide; flexible substrates; photoluminescence; exciton dynamics; tensile strain; transition metal dichalcogenides
Manuscript Timeline: Received: October 14, 2013; Revised: November 25, 2013; Accepted: December 12, 2013; Published: January 15, 2014
Citation: Kim, Y. S., & Vigneron, J. L. (2014). Optical Properties and Exciton Dynamics of Monolayer Molybdenum Disulfide on Flexible Substrates. International Journal of Physics, 5(1), 1–8.
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