Broadband Tunable Photonic Crystal Lasers Based on Quasi‐2D Perovskites in Green Spectral Region

Abstract Photonic crystal (PhC) lasers offer significant advantages in terms of wavelength tuning, mode control, and reduction of lasing thresholds, arising from their unique photonic band structure. However, the development of perovskite‐based PhC lasers in the green light band remains a challenging endeavor, limited by factors such as device structural accuracy, material gain, and tolerance. Here, this work demonstrates the fabrication of quasi‐2D perovskite‐based PhC laser exhibiting single‐mode lasing with a narrow linewidth of 0.9 nm, a high Q‐factor of 622, and an ultralow threshold of 10 µJ cm −2 . By precisely adjusting the hole diameter to the period ratio of the PhC structure, broadband wavelength tuning is achieved across the green spectral region, spanning 30 nm with an accuracy of 1 nm. Furthermore, both surface and edge emission configurations are observed during wavelength tuning, demonstrating the versatility of this device. These results highlight the versatility and potential of quasi‐2D perovskite‐based PhC lasers for applications in sensing, display, communication, and on‐chip integration.