Excitonic absorption and defect-related emission in three-dimensional MoS(2) pyramids

MoS(2) micro-pyramids have demonstrated interesting properties in the fields of photonics and non-linear optics. In this work, we show the excitonic absorption and cathodoluminescence (CL) emission of MoS(2) micro-pyramids grown by chemical vapor deposition (CVD) on SiO(2) substrates. The excitonic absorption was obtained at room and cryogenic temperatures by taking advantage of the cathodoluminescence emission of the SiO(2) substrate. We detected the CL emission related to defect intra-gap states, localized at the pyramid edges and with an enhanced intensity at the pyramid basal vertices. The photoluminescence and absorption analysis provided the Stokes shift of both the A and B excitons in the MoS(2) pyramids. This analysis provides new insights into the optical functionality of MoS(2) pyramids. This method can be applied to other 3D structures within the 2D materials family.