关键词: negative electron affinity semiconductor, secondary electron emission, photoemission, the probability, secondary electron yield, large mean escape depth of excited electrons

Abstract: The formulae for parameters of a negative electron affinity semiconductor (NEAS) with large mean escape depth of secondary electrons $\lambda $ (NEASLD) are deduced. The methods for obtaining parameters such as $\lambda $, $B$, $E_{\rm pom}$ and the maximum $\delta $ and $\delta $ at 100.0 ${\rm keV} \ge E_{\rm po} \ge 1.0 $ keV of a NEASLD with the deduced formulae are presented ($B$ is the probability that an internal secondary electron escapes into the vacuum upon reaching the emission surface of the emitter, $\delta $ is the secondary electron yield, $ E_{\rm po}$ is the incident energy of primary electrons and $E_{\rm pom}$ is the $E_{\rm po}$ corresponding to the maximum $\delta $). The parameters obtained here are analyzed, and it can be concluded that several parameters of NEASLDs obtained by the methods presented here agree with those obtained by other authors. The relation between the secondary electron emission and photoemission from a NEAS with large mean escape depth of excited electrons is investigated, and it is concluded that the presented method of obtaining $\lambda $ is more accurate than that of obtaining the corresponding parameter for a NEAS with large $\lambda_{\rm ph}$ ($\lambda_{\rm ph}$ being the mean escape depth of photoelectrons), and that the presented method of calculating $B$ at $E_{\rm po} > 10.0 $ keV is more widely applicable for obtaining the corresponding parameters for a NEAS with large $\lambda_{\rm ph}$.

Key words: negative electron affinity semiconductor, secondary electron emission, photoemission, the probability, secondary electron yield, large mean escape depth of excited electrons