THEORETICAL RESEARCH OF SECONDARY ELECTRON EMISSION FROM NEGATIVE ELECTRON AFFINITY SEMICONDUCTORS
Abstract
Based on primary range R, relationships among parameters of secondary electron yield δ and the processes and characteristics of secondary electron emission (SEE) from negative electron affinity (NEA) semiconductors, the universal formulas for δ at 0.1keV≤Ep≤10keV and at 10keV≤Ep≤100keV for NEA semiconductors were deduced, respectively; where Ep is incident energy of primary electron. According to the characteristics of SEE from NEA semiconductors with 2keV≤Epmax≤5keV, R, deduced universal formulas for δ at 0.1keV≤Ep≤10keV and at 10keV≤Ep≤100keV for NEA semiconductors and experimental data, special formulas for δ at 0.5Epmax≤Ep≤10Epmax of several NEA semiconductors with 2keV≤Epmax≤5keV were deduced and proved to be true experimentally, respectively; where Epmax is the Ep at which δ reaches maximum secondary electron yield. It can be concluded that the formula for B of NEA semiconductors with 2keV≤Epmax≤5keV was deduced and could be used to calculate B, and that the method of calculating the 1/α of NEA semiconductors with 2keV≤Epmax≤5keV is plausible; where B is the probability that an internal secondary electron escapes into vacuum upon reaching the surface of emitter, and 1/α is mean escape depth of secondary electron.
