DOI: 10.5061/dryad.jdfn2z3j9
title: Data from: Direct quantification of ion composition and mobility in organic mixed ionic-electronic conductors

description: Ion transport in organic mixed ionic-electronic conductors (OMIECs) is
 crucial due to its direct impact on device response time and fundamental
 operating mechanisms but are often assessed indirectly or rely on extra
 assumptions. Operando X-ray fluorescence (XRF) is a powerful, direct probe
 useful for elemental characterization of bulk OMIECs, and was employed to
 directly quantify ion composition and mobility in a model OMIEC,
 PEDOT:PSS, during device operation. The first cycle revealed slow
 electrowetting and cation-proton exchange. Subsequent cycles showed rapid
 response with minor cation fluctuation (~5%). Comparison with
 optical-tracked electrochromic fronts revealed a mesoscale structure
 dependent proton transport. The calculated effective ion mobility
 demonstrated thickness-dependent behavior, emphasizing an interfacial ion
 transport pathway with a higher mobile ion density. The decoupling of bulk
 and interfacial effects on ion mobility, and the decoupling of cation and
 proton transport contributes to our understanding of ion transport in
 conventional and emerging OMIEC-based devices, and has broader
 implications for ion transport in other ionic conductors writ large.
description: We collected the XRF data in beamline 5-BMD, Advanced Photon
 Source, Argonne National Lab using operando XRF method that we developed.
 The UV-Vis results were collected with a halogen white light source (Ocean
 Optics, DH-2000-BAL) and an optical fiber to UV-visible (Ocean Optics,
 FLAME-S) spectrometers with 200 ms integration times.
description: **README: Direct quantification of ion composition and mobility in organic
 mixed ionic-electronic conductors**
 [https://doi.org/10.5061/dryad.jdfn2z3j9](https://doi.org/10.5061/dryad.jdfn2z3j9) In this dataset, we have included the operando X-ray fluorescence collected at beamline 5-BMD (Advanced Photon Source, Argonne National Laboratory). The X-ray energy used for the measurements was 15 and 15.2 keV. The UV-Vis results were collected with a halogen white light source and an optical fiber to Ocean Optics UV-visible spectrometers with 200 ms integration times.  **Contact Information** Name: R. Wu Affiliations: Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA ORCID ID: [https://orcid.org/0000-0003-2666-6110](https://orcid.org/0000-0003-2666-6110) Email: [ruiheng.wu@northwestern.edu](mailto:ruiheng.wu@northwestern.edu) **Description of the data and file structure** There are two types of zip files. The ones starting with “XRF” are the operando XRF results. The tags after “XRF-” give the sample name. For example, “XRF-5-EG-dropcast” means the XRF spectra for 5% EG mixed PEDOT:PSS. Each spectra name includes a time tag and position number inside. The time tag gives the time after voltage change and is end with ‘s’, ‘min’ or ‘h’. The position tag gives the height of X-ray beam (in unit of mm). For the sample “20-EG-dropcast-composition”, the opening is at 93 mm, while for the rest of the samples, the opening is at 92 mm. The files and folders inside each zip file can be expressed by the following tree: SuppMats_Data \|-- XRF-XXX # Name of the example XRF dataset \| |-- Dedoping # XRF for the dedoping process \| | |-- XXX_[time tag]_[position]_XXX.mcaspm # single spectra with time tag and position \| |-- Redoping # XRF for the redoping process \| | |-- XXX_[time tag]_[position]_XXX.mcaspm # single spectra with time tag and position \| |-- Cycle_XXX # XRF for the cycling process for kinetic measurements \| | |-- XXX_[time tag]_[position]_XXX.mcaspm # single spectra with time tag and position For all the “mcaspm” files, the first 19 channels are SPEC counters. And the first four columns give the florescence counts. The last four columns are empty. The folders starting with “UV-Vis” include all the UV-Vis spectra. The files and folders inside each zip file can be expressed by the following tree: SuppMats_Data \|-- UV-Vis-XXX # Name of the example UV-Vis dataset \| |-- XXX_UVVisA__[spectra order]_\_ [time tag].txt # single spectra with time tag For all the “txt” files, the first column gives the wavelengths, and the second column gives the counts. **Sharing/Access information** The original data will also be posted on NU MRSEC DATA RETRIEVAL (NECTAR) later. **Code/Software** The Python codes are provided in the associated Zenodo repository. Here is the brief description of these five codes, following the work flow: 1\. “XRF_Peak_Fitting_Dataset_Rb_20EG_Position_87 - DedopingS.ipynb” is for the peak fitting of sulfur peak to get a per second sulfur XRF count. This is to decrease the noise level for single spectra. 2\. “XRF_Peak_Fitting_Dataset_Rb_20EG_dropcast_Position_87_Dedope.ipynb” is for the peak fitting of As, Rb and (possible) Br peaks in the dedoping and redoping processes. After that, we use the per second sulfur XRF count from the Step 1 to calculate the real Rb-S ratio and possible Br-S ratio. 3\. “XRF_Peak_Fitting_Dataset_Rb_20EG_Position_87_Cycle.ipynb” is for the peak fitting of As, Rb and (possible) Br peaks in the cycling process for kinetic measurements. 4\. “Kinetic fitting.ipynb” reads the results from Step 3 and fits the kinetic curve. This code gives the moving front time at different heights. 5\. “Read UVVis files - 20-EG-6mm.ipynb” reads and smooth the original UV-Vis spectra.