Room-temperature charge localization in ion-coupled bilayer transistors.

Controlling the localization of mobile charges in solids enables the discovery of correlated physical phenomena, but applying it for the development of next-generation electronics requires achieving such control under practical conditions. In this study, we report room-temperature, switchable charge localization in high-quality bilayer transistors that comprise a monolayer of molecular crystal on top of a monolayer semiconductor. By using an ion gate, we selectively populated either localized molecular states or semiconductor band states, achieving complete localization from mobile charges at densities up to 3 × 1013 per square centimeter. This transition was energetically stabilized by the formation of coupled electron-ion dipoles, which could be tuned through Coulomb engineering. These properties further enabled single-band ambipolar transistor operation without substitutional dopants, demonstrating the potential of electron-ion correlations for practical electronic applications. Editor's summary: The localization of mobile charges in solids is crucial for understanding various correlated electron transport phenomena. However, current methods depend on weak interaction potentials, restricting their effectiveness to low-temperature environments. Gao et al. developed ion-gated bilayer transistors using hybrid bilayer crystals consisting of a monolayer molecular crystal atop a monolayer of molybdenum disulfide. This configuration allowed both negative and positive charges in close proximity to each other to form coupled electron-ion dipoles, enabling charge localization robust enough to function at room temperature and high charge densities. This work offers new opportunities for taking advantage of correlated electron transport phenomena, which may have both fundamental and practical implications in solid-state physics, materials science, physical chemistry, and modern electronics. —Yury Suleymanov [ABSTRACT FROM AUTHOR]