Coherent Acoustic Wave Propagation in Two-Dimensional Metal Halide Perovskites

I will discuss our recent efforts on the development of spatiotemporal optical imaging techniques to examine coherent strain waves in quasi-two-dimensional (2D) metal halide perovskites (MHPs). Specifically, I will describe our experiments performed on a variety of 2D MHPs with different number of octahedral layers, where the experiments employ hyperspectrally-resolved pump and probe pulses and cover a unique nanosecond-to-microsecond time range. The effects of the choices on the halides and the organic cations will be discussed as well. If time permits, I will also discuss our results on the self-trapped excitons in double perovskites examined by optical-pump x-ray diffraction experiments.