Localized emission from defects in MoSe_2 layers

Two-dimensional semiconducting analogues of graphene, like monolayer molybdenum diselenide (MoSe2), provide a rich platform for optoelectronics. We study sharp localized photoluminescence (PL) emission from exfoliated MoSe2 flakes. These emission signatures are present in single layers as well as bi- and few layer flakes at low temperatures. The PL from these defects saturate at a lower power than the neutral and charged excitons of the monolayer MoSe2 and are stable against multiple heating and cooling cycles. We study the Zeeman effect in these emitters through magneto-optical photoluminescence studies and derive a g-factor of around 4 which is similar to the delocalized excitons in MoSe2.