Fig. 3

C-V characteristics measured from nanotube TFTs with underlap gates. a Optical micrographs of underlap gate devices with different gate length of 3 μm (top), 8 μm (middle), and 16 μm (bottom). b C-V characteristics for devices (L = 20 μm, W = 200 μm) with different network densities measured at a frequency of 100 kHz. c Unit-area gate capacitance extracted from the measured C-V characteristics (red circle), calculated from parallel-plate model (black dashed line), and calculated from cylindrical model (blue dash line) plotted as a function of nanotube network density. d Device mobility extracted using the experimentally measured gate capacitance, plotted as a function of channel length and for different deposition times