Fig. 4. Vertically stacked complementary circuits based on vOECTs.
a, Illustration of a VSCI based on vOECTs (OSC = organic semiconductor). b, Top view of the VSCI, for which the Au electrode locations are indicated. c, Voltage output characteristics of the VSCI, along with the voltage gain. d, Switching stability of the VSCI with a switching frequency of 10 Hz. e,f, Photograph of a five-stage ring oscillator (e) and the corresponding output characteristics (f). g–i, Photograph of NAND (g) and NOR (h) circuits, and the corresponding voltage input/output characteristics (i). j, Photograph of a rectifier and the corresponding output characteristics (k). Note, in photographs g,h and i, the electrolyte and Ag/AgCl are omitted to provide a better view of the channel areas.