Effect of DC bias during contact electrification of muscovite mica using tapping mode AFM-KPFM

Abstract

A microscopic level study of contact electrification of cleaved muscovite mica disk was performed using a tapping mode scanning system of the atomic force microscope. Using a fixed amplitude set point, and scan speed, image of surface potential during contact electrification was recorded using Kelvin Probe Force Microscope for both negative and positive dc biasing of the n- type Silicon tip. Surface potential sign flip was observed to when the dc biased was increased from 0 to ±3 V. These changes in the surface potential is attributed to energy band-bending and charge back tunneling between mica and n- type Silicon tip during contact electrification