Gain-switching

Materials science

Refractive index

Thermal conductivity

Perovskite (structure)

Wavelength

Polariton

Laser

Continuous wave

Physics

Exciton

Optics

Condensed matter physics

Composite material

Crystallography

Chemistry

Lasing threshold

Optoelectronics

Nano Letters

Lead halide perovskites have emerged as excellent optical gain materials for solution-processable and flexible lasers. Recently, continuous-wave (CW) optically driven lasing was established in perovskite crystals; however, the mechanism of low-threshold operation is still disputed. In this study, CW-pumped lasing from one-dimensional CsPbBr3 nanoribbons (NBs) with a threshold of ∼130 W cm-2 is demonstrated, which can be ascribed to the large refractive index induced by the exciton-polariton (EP) effect. Increasing the temperature reduces the exciton fraction of EPs, which decreases the group and phase refractive indices and inhibits lasing above 100 K. Thermal management, including reducing the NB height to ∼120 ± 60 nm and adopting a high-thermal-conductivity sink, e.g., sapphire, is critical for CW-driven lasing, even at cryogenic temperatures. These results reveal the nature of ultralow-threshold lasing with CsPbBr3 and provide insights into the construction of room-temperature CW and electrically driven perovskite macro/microlasers.

Role of the Exciton–Polariton in a Continuous-Wave Optically Pumped CsPbBr<sub>3</sub> Perovskite Laser

Role of the Exciton–Polariton in a Continuous-Wave Optically Pumped CsPbBr3 Perovskite Laser

Role of the Exciton–Polariton in a Continuous-Wave Optically Pumped CsPbBr₃ Perovskite Laser