Investigating the effect of strain on the optical properties of WSe2 flakes, from bulk to mono-layers - Combining high-resolution μXRD and XEOL

High-resolution micro-XRD measurements allow to obtain the hexagonal unit cell dimensions of WSe2 flakes with different thicknesses (from few mono-layers to bulk). The evaluation of the XEOL signal will provide knowledge about the optical emission properties at the very same sample position. This will give an important contribution to a better understanding of the physics behind those complex, two-dimensional semiconductors. The use of synchrotron light is necessary since for the small scattering volumes and flake sizes (50-100 μm), conventional lab sources are not capable of delivering the required dimension and brightness of the x-ray beam for successful diffraction measurements. Furthermore, XEOL, which will be measured simultaneously, requires the intense synchrotron radiation to trigger the rather inefficient photon conversion processes resulting in the luminescence of the sample.