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An illustration of the strain orientation in the monolayer MoS 2 and a model of band splitting and bandgap modifications of the spin-flip mechanism for two-dimensional MoS 2 monolayer subjected to a periodic strain. [Display omitted] • Application of periodic nanostructures introducing strain into 2D MoS 2 resulted in: • Modulation of the band gap anisotropy. • Removal of degeneracy of the band structure of MoS 2 at the K-point of the Brillouin zone. • Opening of a new approach for bright-to dark exciton conversion. In this study, we investigated the effect of periodic uniaxial strains on electron and phonon transports of polycrystalline and single-crystal molybdenum disulphide (MoS 2) monolayers on a periodically corrugated sapphire surface. Analysis of micro-Raman, polarized photoluminescence and second harmonic generation results shows the anisotropy of the corrugation-induced strain in both single- and polycrystalline MoS 2 monolayers. AFM topography measurements show periodically-rippled surfaces of the MoS 2 in the nanometre scale. Our results show that the application of the periodic strain produces two major effects on the band structure of MoS 2 monolayers: modulations on the band gap anisotropy and reduction of out-of-plane spin-relaxation time due to substrate-induced bending of MoS 2. Spin memory loss, in other words, shortening the spin relaxation time, enables an electron spin-flip scattering process that can convert a formerly bright exciton to a dark exciton. Such conversion is reflected in decreasing intensity of photoluminescence and in the light intensity collected by scanning near-field microscope. Our results demonstrate the ability to control both the bandgap and exciton character in monolayer MoS 2 via periodic strains imposed by corrugated sapphire substrates. This approach offers an effective means in designing novel electronic devices for photovoltaic applications. The bright-to-dark excitons conversion in photovoltaic devices can boast longer lifetimes than their bright exciton counterparts so they can be more efficiently collected by external electrodes. The strain-induced conversion of the bright-to-dark excitons makes the hybrid MoS 2 /corrugated sapphire structure an interesting platform for future photovoltaic applications. [ABSTRACT FROM AUTHOR]