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Semiconductor nanowire (NW) lasers is a promising field of research in many scientific groups around the globe. Their main advantages over nanocuboid and microdisk lasers are two naturally formed light outputs and the shape affording the precise pick-and-place integration of the outputs with light couplers to deliver it on a microscale in photonic integrated circuits (PICs). Although there is good progress in epitaxially grown AIIIBV and AIIBV I NW lasers, cost-efficient counterparts are in demand to supersede the former on the market. For this, a decent option could be non-epitaxial all-inorganic halide perovskite NWs demonstrating a low concentration of deep charge carrier trap states and high enough optical gain and refractive index to enable low-threshold high-Q laser generation in a Fabry−Pérot cavity at room temperature. However, optical pumping of NWs by continuous wave or pulsed excitation at a high repetition frequency is, most likely, supposed to occur in photonic devices that might result in deterioration of NWs photoluminescence, in particular lasing. Herein, we report on the temporal stability of laser and spontaneous emission in a series of mixed-halide CsPb(Cl,Br)3 perovskite NWs grown on a sapphire substrate by sublimation method. We identify a threshold fluence for isolated NWs upon fs pulsed UV-laser excitation at low repetition frequency and, then, examine them at 100 kHz. It is established that an increase in Cl content in the crystal lattice not only shortens a period of lasing observation but also results in halide segregation phenomena.
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