Figure 1. Piezoelectric potential induced by the AFM probe. ( a ) Generation of piezoelectric potential by deflection of the ZnO nanorod, ( b ) current passing through the metal-coated AFM tip in contact with the ZnO nanorod, ( c ) topography and C-AFM signals during the process in ( a ). The current signals originating from the piezoelectric potential are detected when the AFM tip touches the compressed side of an n-type ZnO nanorod 1,9