Name and DOI of manuscript: The effect of residual palladium on the performance of organic electrochemical transistors, https://doi.org/10.1038/s41467-022-35573-y

Data acquisition: Details on the methods of data acquisition are described in the Supporting Information of the manuscript.

Data analysis: Details of the data analysis are described in the above manuscript.

Data availability
Data measured and treated by the Banerji group and shown in the main manuscript is made publicly available in the BORIS repository of the University of Bern. For raw data, S.I. data and data acquired by collaborators, please contact the authors (available upon request). 

Figure1
Measured and treated by collaborators. Please contact the corresponding author (*iain.mcculloch@chem.ox.ac.uk).

Figure2
Measured and treated by collaborators. Please contact the corresponding author.

Figure3
Spectroelectrochemical measurements for the highest performing fraction of each polymer. UV-Vis absorption measurements recorded whilst applying a voltage vs Ag/AgCl using a 0.1 M NaCl aqueous degassed electrolyte, with potential steps of 0.1 V. a) Fraction 3 of p(g4T2-TT) between -0.2 and +0.8 V vs Ag/AgCl and b) fraction 2 of p(C6g3NDI-T) between 0 and -0.8 V. The unpurified and other fractions for each polymer are shown in Supplementary Figure 20.

Figure 3a: UV-Vis absorption measurements recorded whilst applying a voltage vs Ag/AgCl using a 0.1 M NaCl aqueous degassed electrolyte, with potential steps of 0.1 V for fraction 3 of p(g4T2-TT) between -0.2 and +0.8 V vs Ag/AgCl.

Sample preparation: 5mg/mL CHCl3 solution stirred 30 min at 40¡C away from light at air. ITO substrates (Ossila) sequentially cleaned by sonication in Hellmanex III, bi-distilled H2O, acetone and isopropyl alcohol, 10 min each. The substrates were then UV/O3 cleaned for 30 min. All solutions were spin-coated (500 rpm/90 s) at 40¡C on room temperature substrates in ambient conditions. The reference of the sample of fraction 3 of p(g4T2-TT) in Figure 3a is OB126.

Treated data file provided: OB126_SpectraVsVoltage.txt (17/12/2021)

How to read the data file provided:
1st column = Voltage vs Ag/AgCl (in OECT convention, i.e., working electrode is grounded => positive voltage = dedoping, negative voltage = doping)
1st line = wavelength
Next lines = corresponding absorbance (absorbance unit)

Corresponding raw data: OB126_Dalt08.txt (17/11/2021) measured using the ÒFlame setupÓ
Person who measured: Olivier Bardagot
Reference to lab book: Notebook number 2, page 36

Figure 3b: 
Measured and treated by collaborators. Please contact the corresponding author.

Figure 4
Measured and treated by collaborators. Please contact the corresponding author.

Figure 5:
Measured and treated by collaborators. Please contact the corresponding author.

Figure 6:
Measured and treated by collaborators. Please contact the corresponding author.