Fig. 1: Bilayer vOECT characterization.
a Diagram detailing the in-series connection of the bilayer materials structure and the equivalent circuit using variable resistors (Rn for n-type resistance and Rp for p-type resistance). b Materials for each layer of the bilayer are included where the n-type BBL represents the red bottom layer and the p-type PEDOT:PSS represents the blue top layer. c Schematic of the bilayer vOECT structure, where top and bottom electrodes are separated by the bilayer within the active area, or an insulating parylene layer outside the channel, and the top electrode is passivated using a photoresist layer. SEM image of the device is included for reference. d XPS data from the materials bilayer where sulfur (blue) indicates the presence of PEDOT:PSS and nitrogen (red) indicates the presence of BBL. e Transfer curves of the BBL-PEDOT bilayer, BBL, and PEDOT vOECTs overlaid with a prediction of the BBL-PEDOT bilayer using the circuit in (a). (W = 100 µm, VDS = 0.1 V) (f) Change in full width at half maximum with differing ratios of BBL to PEDOT thickness. There is no statistically significant difference in FWHM (n > 5, p = 0.12). g Change in peak Position with differing ratios of BBL to PEDOT thickness. There are statistically significant differences for peak position (one-way ANOVA with Tukey post hoc test p < 0.05, n > 5, p = 0.015). Both panel (f, g) display mean (diamond), median (line), quartiles (box), and 5–95 whiskers.
