Figure 4. Scatter plot of current and lateral force signals. During a typical C-AFM measurement, a constant normal force was applied to the ZnO nanorods. The magnitude of the lateral force applied to the nanorods changed continuously. While completing one raster scan, two sets of C-AFM and LFM signals were simultaneously obtained from every data point on the sample surface. The scatter plot composed of these two distinct signals provides useful information for the mechanism of current