A critique of contact charge spectroscopy: A response

Abstract

Comparison of the experimental parameters used in a recent set of contact charge exchange measurements by Lowell, Rose-Innes, and El-Kazzaz with those used earlier by Fabish, Saltsburg, and Hair reveals that the former correspond to the shallow injection (d∼1 nm) of small amounts of charge and the latter to the deeper (d∼2 μm) injection of larger amounts of charge. These differences suggest that the former results should be interpreted in terms of rapid charge sharing after injection (i.e., nonadditive transfer) whereas the latter should yield results characteristic of noncommunicating, nonequilibrium injected charges (i.e., additive transfer under certain conditions). They also reveal the importance of a careful analysis of the noise inherent in contact charge exchange measurements.