Plasmon–exciton interactions in low-dimensional semiconductors: unlocking bright emission from various exciton states

The emergence of low-dimensional (low-D) semiconductors has transformed materials science, expanding the scope of optoelectronic phenomena from bulk structures to 2D, 1D, and 0D systems. A new frontier is now unfolding through their integration with plasmonic materials and devices. Plasmon–exciton coupling offers effective routes to overcome intrinsic limitations of 2D semiconductors, including low quantum yield, rapid exciton diffusion, and restricted valley control, thereby opening pathways toward practical implementations. We highlight recent advances in plasmon-enhanced emission across a variety of excitonic species and summarize strategies for tailoring exciton dynamics to achieve bright emission. We further discuss plexciton formation and emission in different coupling regimes, as well as emerging approaches for plasmon-mediated valley polarization control. Special emphasis is placed on how plasmonics enables access to otherwise optically forbidden states, such as dark and localized excitons, through polarization-selective detection, strain engineering, and related techniques. Finally, we examine plasmon-driven energy-conversion mechanisms mediated by charged excitons and the distinctive optical and electronic responses of interlayer excitons in van der Waals heterostructures. Together, these advances establish low-D semiconductors coupled to plasmonic architectures as a versatile platform for next-generation light–matter interactions and optoelectronic technologies.