DOI: 10.5061/dryad.zs7h44jkd
title: Correlated nanoimaging of structure and dynamics of cation-polaron coupling in hybrid perovskites

description: Hybrid organic-inorganic perovskites exhibit high photovoltaic performance
 and other novel photonic functions. While polaron formation is believed to
 facilitate efficient carrier transport, the elementary processes of the
 underlying electron-lattice coupling are yet poorly understood because of
 the multi-scale chemical and structural heterogeneities. Here, we resolve
 in the combined ground and excited state spatio-spectral ultrafast
 nanoimaging how structural characteristics are related to both molecular
 cation and polaron dynamics. We observe nano-scale spatial variations of
 the formamidinium (FA) cation transient vibrational blue shifts used as a
 local probe of the non-local polaron-cation coupling. From the correlation
 with nano-movies of the polaron dynamics, we then infer how a softer more
 polarizable lattice supports stabile polarons and longer-lived residual
 carriers. This, together with a relative intra-grain homogeneity in
 contrast to high inter-grain heterogeneity thus suggests pathways for
 improved synthesis and device engineering, and that perovskite photonics
 performance is still far from any fundamental limits.
description: This dataset was obtained by using a heterodyne pump-probe
 infrared scanning-scattering near field optical microscopy technique (HPP
 IR s-SNOM) as established in prior works [Nishida J. et al.,
 Nature Communications <strong>13</strong>, 1083 (2022)]
 to resolve on nanometer spatial and ps temporal scales
 interactions between carriers and lattice vibrations in perovskite films,
 providing a way to optimize materials synthesis efforts by controlling
 material properties that lead to enhanced photovoltaic
 performance.
description: # Correlated nanoimaging of structure and dynamics of cation-polaron
 coupling in hybrid perovskites
 [https://doi.org/10.5061/dryad.zs7h44jkd](https://doi.org/10.5061/dryad.zs7h44jkd) ## Description of the data and file structure The file structure of `Data.zip` is as follows: ``` Data.zip ├── Excited State │   ├── 2023_08_01_FADMACs_Spectra_Spots │   │   ├── 230801 PP │   │   │   ├── 230801-FADMACs-pos1-Max-0 │   │   │   ├── 230801-FADMACs-pos2_Max-0 │   │   │   ├── 230801-FADMACs-pos2_Min-0 │   │   │   ├── 230801-FADMACs-timetrace-pos3-max-0 │   │   │   ├── 230801-FADMACs-timetrace-pos3-min-0 │   │   │   ├── 230801-FADMACs-timetrace-pos4-max-0 │   │   │   ├── 230801-FADMACs-timetrace-pos4-min-0 │   │   │   ├── 230801-FADMACs-timetrace-pos5-max-0 │   │   │   ├── 230801-FADMACs-timetrace-pos5-min-0 │   │   │   ├── 230801-FADMACs-timetrace-pos6-max-0 │   │   │   ├── 230801-FADMACs-timetrace-pos6-min-0 │   │   │   ├── 230801-FADMACs_Pos1_Max-0 │   │   │   ├── 230801-FADMACs_Pos1_Min-0 │   │   │   ├── 230801-Ge-ref-1ps-0 │   │   │   └── 230801-Ge-ref-1ps-1 │   │   └── 230801 SNOM │   │   ├── 230801-FADMACs-pos1-1ps-0 │   │   ├── 230801-FADMACs-pos1-1ps-1 │   │   ├── 230801-FADMACs-pos1-1ps-2 │   │   ├── 230801-FADMACs-pos3_1ps-0 │   │   ├── 230801-FADMACs-spectra-pos1-1ps-0 │   │   ├── 230801-FADMACs-spectra-pos4-1ps-0 │   │   ├── 230801-FADMACs-spectra-pos4-5ps-0 │   │   ├── 230801-FADMACs-spectra-pos5-1ps-0 │   │   ├── 230801-FADMACs-spectra-pos6-0 │   │   ├── 230801-FADMACs-timetrace-pos4-max-0 │   │   ├── 230801-FADMACs_Pos1_5ps-0 │   │   ├── 230801-Ge-0 │   │   ├── 230801-Ge-1 │   │   ├── 230801-Ge-2 │   │   ├── 230801-Ge-ref-1ps-0 │   │   ├── 230801-Ge-ref-1ps-forreal-0 │   │   ├── 230801-Ge-test-0 │   │   ├── 230801-Ge-test-1 │   │   ├── 230801-Ge-test-10 │   │   ├── 230801-Ge-test-11 │   │   ├── 230801-Ge-test-2 │   │   ├── 230801-Ge-test-3 │   │   ├── 230801-Ge-test-4 │   │   ├── 230801-Ge-test-5 │   │   ├── 230801-Ge-test-6 │   │   ├── 230801-Ge-test-7 │   │   ├── 230801-Ge-test-8 │   │   └── 230801-Ge-test-9 │   ├── 2023_08_08-FADMACs-Spectra │   │   ├── 230808 PP │   │   │   ├── 230808-FADMACs_Timetrace_Max_Pos1-0 │   │   │   ├── 230808-FADMACs_Timetrace_Max_Pos2-0 │   │   │   ├── 230808-FADMACs_Timetrace_Min_Pos1-0 │   │   │   ├── 230808-FADMACs_Timetrace_Min_Pos2-0 │   │   │   ├── 230808-FADMACs_Timetrace_Pos1_Max-0 │   │   │   ├── 230808-FADMACs_Timetrace_Pos3-Max-0 │   │   │   ├── 230808-FADMACs_Timetrace_Pos3-Min-0 │   │   │   ├── 230808-FADMACs_Timetrace_Pos4-Max-0 │   │   │   ├── 230808-FADMACs_Timetrace_Pos4-Min-0 │   │   │   ├── 230808-FADMACs_Timetrace_Pos5_Max-0 │   │   │   ├── 230808-FADMACs_Timetrace_Pos5_Min-0 │   │   │   └── 230808-Ge-Ref_1ps-0 │   │   └── 230808 SNOM │   │   ├── 230808-FADMACs_1ps_Pos1-0 │   │   ├── 230808-FADMACs_1ps_Pos4-0 │   │   ├── 230808-FADMACs_1ps_Pos5-0 │   │   ├── 230808-FADMACs_5ps_Pos1-0 │   │   ├── 230808-FADMACs_Spectra_Pos2-1ps-0 │   │   ├── 230808-FADMACs_Spectra_Pos2-1ps-1 │   │   ├── 230808-FADMACs_Spectra_Pos2-1ps-2 │   │   ├── 230808-FADMACs_Spectra_Pos2-2.5ps-0 │   │   ├── 230808-FADMACs_Spectra_Pos3-1ps-0 │   │   ├── 230808-FADMACs_Spectra_Pos3-1ps-1 │   │   ├── 230808-FADMACs_Spectra_Pos3-5ps-0 │   │   ├── 230808-Ge-Ref_1ps-0 │   │   ├── 230808-Ge-pp-test-0 │   │   ├── 230808-Ge-pp-test-1 │   │   ├── 230808-Ge-pp-test-2 │   │   ├── 230808-Ge-test-0 │   │   ├── 230808-Ge-test-1 │   │   ├── 230808-Ge-test-2 │   │   ├── 230808-Ge-test-3 │   │   └── 230808-Ge-test-4 │   ├── 2023_08_10_FADMACs_Spectra │   │   ├── 2023_08_10_Movie │   │   ├── 230810 PP │   │   │   ├── 230810-FADMACs-pos1-max-0 │   │   │   ├── 230810-FADMACs-pos1-max-1 │   │   │   ├── 230810-FADMACs-pos1-max-2 │   │   │   ├── 230810-FADMACs-pos1-min-0 │   │   │   ├── 230810-Ge_test-0 │   │   │   └── 230810-Ge_test-1 │   │   └── 230810 SNOM │   │   ├── 230810-FADMACs-GS-0 │   │   ├── 230810-FADMACs-GS-1 │   │   ├── 230810-FADMACs-pos1-10ps-0 │   │   ├── 230810-FADMACs-pos1-1ps-0 │   │   ├── 230810-FADMACs-pos1-1ps-1 │   │   ├── 230810-FADMACs-pos1-2.5ps-0 │   │   ├── 230810-FADMACs-pos1-2.5ps-1 │   │   ├── 230810-FADMACs-pos1-20ps-0 │   │   ├── 230810-FADMACs-pos1-5ps-0 │   │   ├── 230810-FADMACs-pos2-1ps-0 │   │   ├── 230810-FADMACs-pos2-test-0 │   │   ├── 230810-FADMACs-pos2-test-1 │   │   ├── 230810-FADMACs-test-0 │   │   ├── 230810-FADMACs-test-1 │   │   ├── 230810-Ge-ref-2ps-0 │   │   ├── 230810-Ge-ref-2ps-1 │   │   ├── 230810-Ge-ref-GS-0 │   │   ├── 230810-Ge_test-0 │   │   ├── 230810-Ge_test-1 │   │   ├── 230810-Ge_test-2 │   │   ├── 230810-Ge_test-3 │   │   └── 230810-Ge_test-4 │   ├── 2023_09_26_FADMACs_SinglePoints │   │   ├── 230926 PP │   │   │   ├── 230926-FADMACs_Pos1_Max-0 │   │   │   ├── 230926-FADMACs_Pos1_Min-0 │   │   │   ├── 230926-FADMACs_Pos2_Max-0 │   │   │   ├── 230926-FADMACs_Pos2_Min-0 │   │   │   ├── 230926-FADMACs_Pos3_Max-0 │   │   │   ├── 230926-FADMACs_Pos3_Min-0 │   │   │   ├── 230926-FADMACs_Pos4_Max-0 │   │   │   ├── 230926-FADMACs_Pos4_Min-0 │   │   │   ├── 230926-FADMACs_Pos5_Max-0 │   │   │   ├── 230926-FADMACs_Pos5_Min-0 │   │   │   ├── 230926-FADMACs_Pos6_Max-0 │   │   │   └── 230926-FADMACs_Pos6_Min-0 │   │   ├── 230926 SNOM │   │   │   ├── 230926-FADMACs_GS-0 │   │   │   ├── 230926-FADMACs_GS-1 │   │   │   ├── 230926-FADMACs_GS-2 │   │   │   ├── 230926-FADMACs_GS-3 │   │   │   ├── 230926-FADMACs_Pos1_1ps-0 │   │   │   ├── 230926-FADMACs_Pos2_1ps-0 │   │   │   ├── 230926-FADMACs_Pos2_1ps-1 │   │   │   ├── 230926-FADMACs_Pos3_1ps │   │   │   ├── 230926-FADMACs_Pos4_1ps-0 │   │   │   ├── 230926-FADMACs_Pos5_1ps-0 │   │   │   ├── 230926-FADMACs_Pos6_1ps-0 │   │   │   ├── 230926-Ge_Ref-0 │   │   │   ├── 230926-Ge_Ref-1 │   │   │   ├── 230926-Test-0 │   │   │   ├── 230926-Test-1 │   │   │   ├── 230926-Test-2 │   │   │   ├── 230926-Test-3 │   │   │   ├── 230926-Test-4 │   │   │   ├── 230926-Test-5 │   │   │   └── 230926-Test-6 │   │   └── AFM │   └── 2023_10_24_FADMACs_Fluence2 │   ├── 231024 PP │   │   ├── 231024-FADMACs_100uW_Max-0 │   │   ├── 231024-FADMACs_100uW_Min-0 │   │   ├── 231024-FADMACs_150uW_Max-0 │   │   ├── 231024-FADMACs_150uW_Min-0 │   │   ├── 231024-FADMACs_200uW_Max-0 │   │   ├── 231024-FADMACs_200uW_Min-0 │   │   ├── 231024-FADMACs_250uW_Max-0 │   │   ├── 231024-FADMACs_250uW_Min-0 │   │   ├── 231024-FADMACs_250uW_Min-1 │   │   ├── 231024-FADMACs_300uW_Max-0 │   │   ├── 231024-FADMACs_300uW_Min-0 │   │   ├── 231024-FADMACs_350uW_Max-0 │   │   ├── 231024-FADMACs_350uW_Min-0 │   │   ├── 231024-FADMACs_400uW_Max-0 │   │   ├── 231024-FADMACs_400uW_Min-0 │   │   ├── 231024-FADMACs_450uW_Max-0 │   │   ├── 231024-FADMACs_450uW_Min-0 │   │   ├── 231024-FADMACs_500uW_Max-0 │   │   ├── 231024-FADMACs_500uW_Min-0 │   │   ├── 231024-FADMACs_550uW_Max-0 │   │   └── 231024-FADMACs_550uW_Min-0 │   ├── 231024 SNOM │   │   ├── 231024-FADMACs_Spectrum_1ps_100uW-0 │   │   ├── 231024-FADMACs_Spectrum_1ps_500uW-0 │   │   └── 231024-GeRef │   └── Fits └── Ground State ├── 2022_08_09_FADMACs ├── 2022_10_21_FADMACs ├── 2022_10_23_FADMACs └── 2022_10_28_FADMACs ``` --- The **Excited State** folder contains data taken *with* visible pump excitation. * Folders with 'PP' in the name contain two-phase heterodyne time traces at various positions on the perovskite surface * `.dat`: These files are time traces, with the following columns in the following order: * Pump delay stage position t_ref (mm), then data channels 1 - 6 which are the signals resulting from demodulating with a lock-in amplifier at the following frequencies respectively: (ν_tip, ν_tip + Ω_M, ν_tip - Ω_M; 2ν_tip, 2ν_tip + Ω_M, 2ν_tip - Ω_M). * 'Max' in the title indicates that the time traces were taken at a maximum delay position (ϕ = 0) of the reference arm. * 'Min' in the title indicates that the time traces were taken at a minimum delay position (ϕ = π) of the reference arm. * 'X' and 'Y' in the title contain the real and imaginary parts of the demodulated signals. * The last number before the file extension in the title indicates a trial number. These trials are averaged together before analysis. * Folders with 'SNOM' in the name contain interferograms taken at various positions on the perovskite surface as well as varying time delays * `.dat`: These files are raw interferograms, with the following columns in the following order: * Reference arm stage position T (µm), then data channels 1 - 6 which are identical to the timetraces as described above. * 'X' and 'Y' in the title contain the real and imaginary parts of the demodulated signals. * A value in ps indicates the fixed pump delay T while the spectra were recorded. * The last number before the file extension in the title indicates a trial number. These trials are averaged together before the analysis * Reference spectra are taken on Ge, and are included in raw interferogram form with 'ref' or 'Ge' in the title. --- The **Ground State** folder contains spectral data taken *without* visible pump excitation. * `.txt`: Raw spectra with reference arm stage positions in µm and signal level in V * `.axz`: Files containing point spectra, array spectra, and atomic force microscopy (AFM) images. There are resources available [here](https://github.com/AnasysInstruments/anasys-python-tools) for working with this format in Python. * `.xml`: Uncompressed form of .axz files. See the directions above. * `.m/.mat`: Spectra processing code and results. Requires MATLAB. * `.png`: Images from Analysis Studio depicting locations of array points overlaid on AFM topography. --- The file structure for `Code.zip` is as follows: ``` Code.zip ├── frames_processing.ipynb ├── sgolay2.py └── spectra_processing.ipynb ``` The purpose of these files is as follows: * `frames_processing.ipynb`: A Jupyter notebook containing analysis code for processing spatiotemporally resolved signal "movies", including stretched exponential fitting for time traces extracted from the frames. * `sgolay2.py`: A python file containing an implementation of the 2D Savitzky–Golay filter for data smoothing. * `spectra_processing.ipynb`: A Jupyter notebook containing analysis code to compare ground and excited state spectra, including Voigt profile fitting.