Ultrafast Carrier Dynamics and Laser Pulse Generation in Halide Perovskite Semiconductors

ABSTRACT Halide perovskites (HPs) are among the most promising semiconductor candidates for ultrashort pulse generation due to their intrinsic high material gain and ultrafast carrier dynamics. By introducing an ingeniously‐designed cavity structure, picosecond (ps) or even femtosecond (fs) laser pulses can be plausibly obtained from the perovskite devices for a wide variety of applications. A comprehensive understand of the carrier density dependence of exciton transport and recombination as well as light‒matter interaction can help researchers gain deeper insight into the ultrashort pulse generation during lasing. Here, an overview of the recent progress on ultrafast charge carrier dynamics in 3D bulk single‐crystal perovskites as well as quantum‐confined 2D/quasi‐2D Ruddlesden–Popper perovskites and 0D perovskite nanocrystals/quantum‐dots is provided. Additionally, state‐of‐the‐art developments in pulse generation from various perovskite lasers are summarized, with particular attention paid to gain‐switched ultrashort laser pulse emission in different HP microcavities. The physical mechanisms that influence the pulse characteristics of HP lasers based on a rate equation model is also discussed. Finally, the challenges and future prospects of HPs in realizing ultrashort fs‐optical pulses for practical applications are discussed emphatically.