Light-assisted precise control of micro-cavity lasers for lead halide perovskite nanorods.

The development of integrated on-chip lasers featuring both low thresholds and high-quality factors remains a fundamental challenge in photonic integrated circuits, particularly for applications requiring visible coherent light sources. To develop micro-/nanolasers with high robustness and reliability, the fabrication of resonant cavities with controllable morphology and size is essential. In this work, we employed a light-assisted self-assembly approach to direct the formation of CsPbBr₃ quantum dots into uniform, high-quality nanorods (NRs). By precisely tuning the illumination time, the growth dynamics of the NRs were effectively regulated, resulting in well-defined resonators with improved light confinement and lasing efficiency. Transient absorption spectroscopy revealed suppressed nonradiative Auger recombination and enhanced radiative bimolecular recombination. These NRs functioned simultaneously as the gain medium and the resonant cavity, enabling nanosecond-sustained amplified spontaneous emission (ASE) (62.49 μJ/cm²) and femtosecond lasing at room temperature.