For electrical characteristics of the conductive film, we utilized the Napson RT-7 four-point probe resistance measurement system to measure sheet resistance.
Electrical conductivity of the aligned SWCNT sheets was calculated from the measured sheet resistance using a four probe electrical measurement tester (Mitsubishi chemical, Loresta-EP MCP-T360) and the average cross-sectional area.
Figure 5a shows the measured sheet resistance of our copper film as a function of time.
The measured sheet resistance was 2.08 kΩ−1 for a monolayer graphene and 1.15 kΩ−1 for GrPyC film.
Table 1 shows the measured sheet resistance and transmittance of the Ag, ITO, and WAW multilayers.
The NNet models well represent the measured sheet resistance, optical transmittance, and the figure of merit.
The deviations of measured sheet resistance values were usually less than ±1%% of the average value at each measuring point.
The measured sheet resistance of 55.5 Ohm/square, multiplied by the film thickness of 1.8 mm, yields 0.01 Ohm cm.
From the measured sheet resistance (Figure 3) and effective layer thickness, it is possible to calculate the layer resistivity R (Ω cm).
where UNI is the sheet resistance uniformity; RsMax, RsMin, and RsAverage, ρ, and t are highest, lowest, and average of measured sheet resistance (ohm/square), resistivity (ohm.cm), and film thickness (cm), respectively.
The measured sheet resistance was 13 Ω/□, and optical transmittance was 86%, including the glass substrate, which was found to be independent of wavelength in the visible spectrum, in contrast with the optical transmittance of ITO.
