Nonvolatile Modulation of Light Emission from Delocalized and Defect-Bound Excitons in Monolayer MoS₂ Using the Remnant Polarization in the Ferroelectric Polymer P(VDF-TrFE): Implications for Optical Memory

Excitons in semiconductors are a potential alternative to charge for manipulation and storage of information. The reduced electrostatic screening in monolayers of two-dimensional (2D) semiconductors increases the binding energies of delocalized (free) excitons, while also encouraging the formation of defect-bound excitons that can be leveraged in devices for neuromorphic and quantum computing. We report the nonvolatile modulation of light emission from delocalized and defect-bound excitons in monolayer MoS 2 using the remnant polarization of P(VDF-TrFE) ferroelectric polymer islands. Photoluminescence emission intensities of delocalized excitons at room-temperature and bound excitons at cryogenic temperatures are enhanced by polarization that depletes free electrons and reduces Coulomb screening. The opposite polarization suppresses emission, providing a simple means of electrically encoding and optically reading information. Two distinct defect-bound exciton bands are identified by their spectral positions and their distinct variations with temperature and polarization, suggesting that they have distinct origins or interactions with the surrounding environment. The selective reconfiguration of free and bound excitonic emission suggests a novel device scheme toward electrically reconfigurable, optically accessible optical memory devices.