Non-Equilibrium Lattice Dynamics in Photo-Excited Two-Dimensional Perovskites

Work performed at the Center for Nanoscale Materials and Advanced Photon Source, both U.S. Department of Energy Office of Science User Facilities, was supported by the U.S. DOE, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. At Northwestern University, this work is supported by the Department of Energy, Office of Science, Basic Energy Sciences, under Grant No. SC0012541 (M.G.K., synthesis, structure, and characterization of physical properties) and by the National Science Foundation Macromolecular, Supramolecular, and Nanochemistry Award No.1808590 for elevated fluence optical investigation. This work made use of the IMSERC facility at Northwestern University, which has received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-2025633), and Northwestern University. Purchase of the Ag-microsource diffractometer used to obtain results included in this publication was supported by the Major Research Instrumentation Program from the National Science Foundation under the Award No. CHE-1920248. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship Program under Grant No. DGE-1842165 (S.P. and A.B.). A.M.L. acknowledges support from by the Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division, under Contract DE-AC02-76SF00515. This work was performed with financial support from the European Union's Horizon 2020 program through an Innovation Action under grant Agreement No. 861985 (PEROCUBE). J.E. acknowledges financial support from the Institute Universitaire de France. This work was granted access to the HPC resources of [TGCC/CINES/IDRIS] under the allocations 2020-A0100911434 and 2020-A0090907682 made by GENCI.