Phenomenological description of excitonic complexes in tip-enhanced photoluminescence of 2D materials

Two dimensional materials exhibit different electronic and optical properties than the corresponding bulk materials. Transition metal dichalcogenides (TMDs) are semiconducting 2D crystals that exhibit unusually strong photoluminescence (PL) signals due to the stability of excitons at room temperature. However, many factors can effect the measured intensity of PL signals including charge doping or the presence of a plasmonic AFM tip. Here we present a set of phenomenological rate equations in order to model the intensity of PL in tip-enhanced experiments involving tip-sample distance dependent measurements and near field imaging. Furthering the understanding of exciton dynamics around heterojunctions of TMDs may lead to the engineering of new optoelectronic devices such as optical transistors, novel optomechanics, and controllable signaling on the nanoscale.