In case of photoemission spectroscopy of an insulating material the data obtained from the charged surface are distorted. Recently a controlled surface neutralization technique has been developed and with the help of an effective model quantitative information from the apparently distorted photoemission data was extracted. It was shown that the neutralization responses of differential charging are non-linear around a critical neutralizing electron flux. Here with a new set of experiments with Poly(tetrafluoroethylene) (PTFE) and analyzing our earlier data of Polystyrene (PS) and Polyacrylamide (PAM) it was shown that the neutralization of charged surfaces are similar to avalanche breakdown process and occurs through the percolation of homogeneously dispersed surface domains.
