Plasmon-enhanced exciton relocalization in quasi-2D perovskites for low-threshold room-temperature plasmonic lasing.

Room-temperature nanolasers are crucial for advancing optical communication and photonic quantum technologies due to their capability to generate coherent light at a subwavelength scale. However, their development is constrained by challenges such as insufficient gain, material instability, and high lasing thresholds. By integrating quasi-two-dimensional (quasi-2D) perovskites with high- plasmonic nanostructures, we demonstrate a stable, wavelength-tunable, single-mode laser operating at room temperature. This device leverages a unique exciton relocalization effect in quasi-2D Ruddlesden-Popper perovskites with additives, substantially enhancing optical gain and improving stability. When coupled with a waveguide-hybridized surface lattice resonance mode, the enhanced light-matter interaction facilitates single-mode lasing with a notably low threshold of 0.9 millijoules per square centimeter. In addition, the device achieves robust lasing performance with extended operational stability (1.8 × 10 excitation pulses). These results provide a scalable, low-cost, and energy-efficient platform for nanolasing, with potential applications in next-generation photonic technologies, including light detection and ranging, sensing, optical communication, and computation.