Exciton dynamics in two dimensional materials

Two-dimensional materials, like transition metal dichalcogenides, are promising for future optoelectronic devices due to their strong optical absorption, wide variety of bandgaps and high chemical stability. Quantum confinement and reduced screening leads to strong excitonic effects in atomically thin materials. Consequently, their optical properties is governed by excitons. Understanding how excitons are formed, move, interact and dissociate at interfaces will be crucial to use such materials in optoelectronic applications. We study the temporal and spatial dynamics of excitons in two-dimensional materials and their heterostructures with ultrafast transient absorption spectroscopy and transient absorption microscopy. The effect of the dielectric environment, strain, chemical treatment and electric field on the exiton formation and their movement will be also studied. The student will make two-dimensional heterostructures using state of the art nanofabrication techniques, participate in the building of an ultrafast transient absorption microscope, and carry out spectroscopic measurement on the aforementioned samples.