Name and DOI of manuscript: Effects of Side-Chain Length and Functionality on Polar Poly(dioxythiophene)s for Saline-Based Organic Electrochemical Transistors, https://doi.org/10.1021/jacs.2c08850 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 by the Banerji group in agreement with data management policies (SNF, Horizon 2020) 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 (*reynolds@chemistry.gatech.edu). Figure2 Measured and treated by collaborators. Please contact the corresponding author. Figure3 Measured and treated by collaborators. Please contact the corresponding author. Figure 4 Designed by collaborators. Figure 5 a) Transconductance values as a function of channel dimensions and biasing parameters of G2-DMP (green triangles), G3-DMP (purple circles), and G4-DMP (orange stars). [?C*]pOECT values are extracted from the slope of the linear fits (y = ax, dashed lines, R2 = 0.99, 0.97, 0.98, for G2-, G3-, G4-DMP respectively, cf Figure S35). All transfer curves are displayed in Figure S33 and were recorded by sweeping VGS from +0.1 V to 0.8V at 5 mV s-1 with fixed VDS = -0.6 V. All values of W, d, L, VGS and VTh are reported in Table S3. b) Comparison of the doping kinetics of G2- (green), G3- (purple), and G4-DMP (orange) in pOECT devices in a degassed 0.1 M NaCl/H2O electrolyte. Temporal evolution of the normalized absorbance at 550 nm upon doping at VGS = 0.8 V with delay removed (detailed in section 6.5 of the SI, Figure S39-40, Table S4) to afford biexponential fitting (solid lines = fits, dotted lines = data), as previously done in literature. c) Transconductance retention of iOECT devices incorporating G2, G3, and G4DMP performed in a three-electrode interdigitated architecture. All iOECT device data were obtained with a hold time of 3 s, a VGS step size of 1mV and a step time of 20ms (comparable to a VGS sweep at a 50 mV s-1 scan rate). pOECT preparation: 20mg/mL CHCl3 solution stirred overnight at room temperature away from light under inert atmosphere. Ultra-flat quartz-coated glass substrates (S151, Ossila) were cleaned by sequential sonication in 2% Hellmanex III, bi-distilled H2O, acetone, and isopropyl alcohol (10 min each), followed by UV/O3 cleaning (30 min). Pre-patterned Cr/Au (10 nm/ 60 nm) electrodes were deposited by thermal evaporation (0.2 s-1/ 1.0 s-1) onto the cleaned substrates to form the source (S) and drain (D) electrodes. Planar organic electrochemical transistors (pOECTs) were fabricated by spin-coating the resulting polymer solution in two subsequent steps (where the first consisted of a ramp to 2000 rpm for 2 s followed immediately by a 1000 rpm hold for 60 s) in ambient conditions onto the S and D electrodes. No post-deposition treatment was performed. The stock solutions were diluted stepwise from 20 to 3 mg/mL to achieve pOECTs with varying thicknesses. A square channel was then defined by removing excess polymer from the S and D electrodes by gently wiping with a high-precision micro-cleaning cleanroom swab (C201, Ossila). The pOECT devices were completed by encapsulating the sample in a hermetic cell together with a Ag/AgCl quasi-reference pellet electrode (Warner Instruments) and filled with Ar-degassed 0.1 M NaCl electrolyte in bi-distilled H2O. All pOECTs were manufactured by Brandon DiTullio on 01/03/2022 and 01/04/2022. Figure 5a The reference of the samples in Figure 5a are: * For G2-DMP: OE2-1_20gL (01/03/2022), OE2_20gL (01/04/2022), OE2-redo_15gL (01/04/2022), OE2_7gL (01/03/2022). * For G3-DMP: OE3_15gL, OE3_10gL, OE3_7gL, OE3_3gL. All on 01/03/2022. * For G4-DMP: OE4_20gL, OE4_15gL, OE4_10gL, OE4_7gL, OE4_3gL. All on 01/03/2022. Person who measured the thickness: Brandon DiTullio. Person who measured the channel width and length: Olivier Bardagot. Reference to Olivier Bardagots lab notebook: Number 2, pages 67, 68 and 73. Persons who acquired the raw data: Brandon DiTullio (BD) and Olivier Bardagot (OB). List of raw data files obtained with the Transfer_characteristics mode using the Flame setup: * OE2_20gL_Trans5.txt (02/03/2022 - OB notebook 2, page 69) * OE2-1_20gL_Trans5.txt (08/04/2022 - BD) * OE2-redo_15gL_Trans5.txt (08/04/2022 - BD) * OE2_7gL_Trans5.txt (25/03/2022 - BD) * OE3_15gL_Trans5.txt (14/03/2022 - BD) * OE3_10gL_Trans5.txt (26/03/2022 - BD) * OE3_7gL_Trans5.txt (27/03/2022 - BD) * OE3_3gL_Trans5.txt (27/03/2022 - BD) * OE4_20gL_Trans5.txt (02/03/2022 - OB notebook 2, page 68) * OE4_15gL_Trans5.txt (03/03/2022 - OB notebook 2, page 70) * OE4_10gL_Trans5.txt (24/03/2022 - BD) * OE4_7gL_Trans5.txt (24/03/2022 - BD) * OE4_3gL_Trans5.txt (24/03/2022 - BD) List of parameters used: Vds: -0.60 V Vgs_min: +0.10 V Vgs_max: -0.80 V Points: 1000 Scan rate: 5 mV s-1 Calculated experiment time: 6.0 min Person who treated all the data using the Python script Plotting_Transfer_Output_OB.ipynb: Olivier Bardagot Treated data file provided: gm_vs_geo_plus_linear_fit_ax.txt (18/11/2022) How to read the data file provided: 1st column = points of the linear fit of G2-DMP 2nd column = points of the x-axis (geometric and bias factors) of G2-DMP 3rd column = points of the y-axis (transconductance gm) of G2-DMP 4th column = points of the linear fit of G3-DMP 5th column = points of the x-axis (geometric and bias factors) of G3-DMP 6th column = points of the y-axis (transconductance gm) of G3-DMP 7th column = points of the linear fit of G4-DMP 8th column = points of the x-axis (geometric and bias factors) of G4-DMP 9th column = points of the y-axis (transconductance gm) of G4-DMP Figure 5b The reference of the samples in Figure 5a are: * For G2-DMP: OE2_7gL. * For G3-DMP: OE3_10gL, OE3_7gL. * For G4-DMP: OE4_7gL. All manufactured on 01/03/2022 by Brandon DiTullio. Person who acquired the raw data: Brandon DiTullio. List of raw data files obtained with the Dalton mode using the Flame setup: OE2_7gL_Dalt08.txt (25/03/2022) OE3_7gL_Dalt08.txt (27/03/2022) OE3_10gL_Dalt08.txt (26/03/2022) OE4_7gL_Dalt08.txt (24/03/2022) List of parameters used: Dwell_ON (s): 5 s Dwell_OFF (s): 30 s Vgs_ON_min: 0.10 V Vgs_ON_max: -0.80 V Vgs_OFF: +0.50 V Vds_ON: 0 V Vds_OFF: 0V Step: 0.10 V Cycles: 1 Integration: 1 Measure Ids?: false (SD contacts short-circuited) Calculated experiment time: 5.83 min Person who treated the data using the Python script Plotting_multiple_samples_OB_August2022.ipynb: Olivier Bardagot List of treated data files corresponding at a wavelength sampling of the absorbance decay at 550 nm upon switching from +0.5 V to -0.8 V vs. Ag/AgCl with the maximum of absorbance normalized to one: OE2_7gL_Dalt08_ON_fit_-0.8.txt (17/08/2022) OE3_7gL_Dalt08_ON_fit_-0.8.txt (17/08/2022) OE3_10gL_Dalt08_ON_fit_-0.8.txt (17/08/2022) OE4_7gL_Dalt08_ON_fit_-0.8.txt (17/08/2022) Description of the treated data .txt file: 1st column = Time in second. Zero corresponds to the voltage switch to -0.8 V 2nd column = Wavelength sampling at 550 nm (absorbance in OD) 3rd column = Biexponential fit of the 2nd column Figure 5c Measured and treated by collaborators. Please contact the corresponding author. Figure 6 Measured and treated by collaborators. Please contact the corresponding author.