DOI: 10.34810/data1911
title: Replication Data for: Structured Excitation Energy Transfer: Tracking Exciton Diffusion below Sunlight Intensity

description: The dataset consists of time-resolved photoluminescence traces that report to the exciton diffusion properties of two different samples: organic photovoltaic material Y6 and single layer membrane of the Light Harvesting 2 (LH2) molecule from purple bacteria. The diffusion properties are recovered by combining TCSPC measurements together high frequency structured illumination and a demodulation scheme that allows to track the temporal dynamics the exciton population at the spatial frequency of the excitation. We included both raw data and MATLAB scripts process the file in order to obtain the mean square displacement data from where the diffusion properties are obtained.

The provided dataset was generated using the StrEET microscopy technique, as described in the publication (https://doi.org/10.1021/acsphotonics.4c00004). Briefly, a high frequency, sine-like, structured illumination (2 ps pulses at 800 nm wavelength) is used to excite the sample in a 42-micron region of interest. The collected photoluminescence is demodulated using a transmission mask of the same period which is mounted in a piezo-electric actuator. Then, the resulting light is detected on a fast SPAD detector for time single photon counting (TCSPC). The setup instrumentation was developed using LABVIEW 2021 and the raw TCSPC histograms are saved in TDMS file format (https://www.ni.com/en/support/documentation/supplemental/06/the-ni-tdms-file-format.html?srsltid=AfmBOoocwwjWt6GMyPIH7ii7g6E6uSVEPIqYPfOSAWwue-wsB9ep6DtO)

The raw data was processed using several MATLAB scripts, specifically created for that purpose. The mathematical description of the data processing (i.e. obtaining the energy transport information from the TCSPC traces) is described in the main article (https://doi.org/10.1021/acsphotonics.4c00004).

Matlab 2015a or later. The functions folder (and subfolders) should be added to Matlab path. Public libraries to open TDMS files with matlab are included.

TCSPC was generated using a standard Picoharp 300 system (PicoQuant)
description: Three folders are provided, corresponding to the two different samples studied in the paper (Y6 and LH2) and an additional folder containing functions required by the analysis programs. For Y6, the raw TDMS files containing the TCSPC traces are provided. Each file name contains the date and time of the experiment (in YYYYMMDD_HHMMSS format) and the average power of the excitation beam at the objective back focal plane. For each individual power, a matlab script is provided that processes the corresponding TDMS files. In the LH2 folder, MATLAB workspace files (.MAT) are provided with the processed results, which are then further processed by the provided matlab script.

File name: Y6\20260623_HHMMSS_power_**.tdms
Description: Raw data including TCSPC traces for Y6 and the metadata of the measurement in TDMS file format. The histograms are interleaved in a single column vector, containing N repetitions of 3300 time steps (4 ps sampling), alternating between in phase and out of phase detection (for the amplitude demodulation). This samples are processed by the process_fluence_*.m scripts.

File name: Y6\process_fluence_**.m
Description: Matlab script that plots the mean square displacement and fits the diffusivity for each excitation fluence. The function folder should be added to path in order for this script to run correctly.

File name: LH2\202307DD_HHMMSS_spot*.mat
Description: Matlab workspace files containing the pre-processed TCSPC time traces for the LH2 samples. Variable S contains the mean square displacement data for time steps tb. These files are processed by the process_LH2.m script.

File name: Y6\process_LH2.m
Description: Matlab script that plots the mean square displacement and fits the diffusivity for all the LH2 measurements at different spots.

Raw data files are in .TDMS file format. This can be opened with the supplied Matlab library

The provided dataset is divided in two folders by type of sample (Y6 and LH2). An additional folder containing functions required for the processing scripts is provided.
description: Matlab, 2015a