Nanoscale Metal–Insulator–Semiconductor Tunnel Junction for Multibit Excitonic Data Storage

The exponential growth of digital information presents a critical challenge for the sustainable data preservation. While optical data storage (ODS) systems have emerged as a promising solution for economical and long-term data archiving, conventional ODS technologies face limitations due to the optical diffraction limit and inability to harness emerging excitonic properties, restricting further improvements in storage density. Here, we demonstrate a multibit excitonic data storage (EDS) system by generating nanoscale metal-insulator-semiconductor tunnel junctions. By precisely modulating the extent of Ohmic contact within these junctions, we control the doping-related exciton recombination dynamics of atomically thin semiconductors. The modulated EDS system exhibits three discrete photoluminescence intensity levels within a unit data-space of ∼60 nm, demonstrating nanoscale multilevel data encoding. Our work provides a strategy for ultrathin nano-EDS technologies for future advancements in archival storage systems.