Room temperature spin light-emitting diode based on chiral 2D superlattice

Room-temperature spin optoelectronics are poised to drive the next generation of spintronic devices, yet conventional approaches to control spin, charge, and light typically require both electrical and magnetic fields. The chiral-induced spin selectivity (CISS) effect has recently emerged as a promising platform for magnet-free spin control in chiral molecules. However, organic chiral systems often suffer from limitations in spin selectivity, polarization efficiency, and long-term stability, challenging the creation of robust, high-performance spintronic systems. Here, we present a magnet-free, room-temperature spin light-emitting diode (spin-LED) using a chiral two-dimensional (2D) superlattice to enable efficient and stable spin polarization via the CISS effect. The chiral superlattice is synthesized by intercalating layered 2D transition metal dichalcogenides (TMDs) with specific chiral molecules, creating a highly ordered superlattice of alternating crystalline atomic layers and self-assembled chiral molecular layers. The spin state of the injected charge carriers is polarized via the CISS effect as they pass through the chiral superlattice, resulting in a high relative spin polarization up to 90 %. These spin-polarized carriers recombine radiatively in the emission layer, producing circularly polarized electroluminescence (CP-EL). The resulting spin-LEDs exhibit a CP-EL polarization degree of ± 16.7 % and an external quantum efficiency of ∼ 18.9 % at room temperature, establishing a viable alternative to conventional spin-LED technologies. Notably, the strategy is extended to different TMDs, demonstrating comparable performance and highlighting the generalizability of the approach. This work establishes chiral 2D superlattices as a versatile platform for optospintronic applications, paving the way toward energy-efficient, magnet-free and room temperature spin-optoelectronic devices.