Ultraviolet-green dual-band lasing action from GaN/CsPbBr₃ hybrid microcavity

Micro-nano lasers are highly desirable in intergrated optoelectronic devices for their compact size, efficient energy conversion, and rapid modulation speed. In this work, GaN/CsPbBr₃ hybrid microcavities are realized by growing square CsPbBr₃ microplate on a substrate of floating GaN microdisk. The growth conditions can be used to control the size of square CsPbBr₃ microplates. Additionally, multi-mode laser output can be achieved in the ultraviolet-green bands using square CsPbBr₃/circular GaN hybrid microcavities. Further, single-mode lasing is realized by utilizing a quasi-semicircular chaotic GaN microdisk integrating with a square CsPbBr₃ microplate with a small size. In the optical pumping lasing process, it is found that the lasing modes of GaN and CsPbBr₃ have an opposite shift. The redshift of GaN lasing and CsPbBr₃ blueshift of lasing can be attributed to their different temperature-dependent refractive index. In addition, wavelength-tunable GaN/CsPbCl_xBr_3-x lasing is obtained around the green emission band by the halide anion exchange method. This study provides a new strategy to realize dual-band microlasers.