THE FORMULAE FOR PARAMETERS OF THE SECONDARY ELECTRON YIELD OF INSULATORS FROM 10 keV TO 30 keV

Abstract

Based on the formula for the average energy required to produce an internal secondary electron (ε) in emitter, the energy band of insulator and the assumption that the maximum exit energy of secondary electron in insulator is reverse to the width of forbidden band, the formula for ε in insulator is deduced. On the basis of the formula for the number of internal secondary electrons produced in the direction of the velocity of primary electrons per unit path length, the energy band of insulator and the characteristic of secondary electron emission, the formula for the probability of secondary electrons passing over the surface barrier of insulator into the vacuum (B) is also deduced. According to some relationship between the parameters of secondary electron yield from insulator, the formula for the mean escape depth (1/α) is successfully deduced. The formulae for ε and 1/α are experimentally proven, respectively, and thereafter the formula for B is indirectly proven to be true by the experimental results. It is concluded that the formulae for ε, B and 1/α are universal to estimate ε, B and 1/α under the condition that primary electrons from 10 keV to 30 keV hit on an insulator, respectively.

Secondary electron emission and photoemission from a negative electron affinity semiconductor with large mean escape depth of excited electrons

“…So far, B in every existing formulae for SEE from a given emitter has been treated as a constant. [8,29,34,55,56] From the above analysis, and the fact that all the experimental δ values for NEASLDs which we can find agree well with corresponding values calculated by the method presented here, we can conclude that δ of NEASLDs calculated using Eqs. ( 21) and ( 22) agree well with the experimental results.…”

“…Thus, λ = 1.0 × 10 5 Å can be obtained from the adopted values of h, H and n 10.0−15.0 , the experimental values δ 10.0 = 287.93 and δ 12.0 = 340 and Eqs. ( 29) and (34). From n 10.0−15.0 = 1.6894, the experimental values δ 12.0 = 340 and δ 14.0 = 389.63 [15] for NEA GaAs and Eqs.…”

“…Therefore, equations ( 8) and ( 9) are fairly suitable for a NEASLD. The average energy required to produce an internal secondary electron in semiconductors or insulators, ε, can be written as [34] ε =…”

“…Because λ of an insulator is of the order of 100 Å, [8,34,42] i.e., λ hot of an insulator due to primary electrons is of the order of 100 Å, the hot electrons excited by primary electrons in an insulator mainly lose energy by electron-electron interaction as those in a NEASLD do, and χ of an insulator is very low or equal to 0. [48] Thus, λ hot of a NEASLD due to primary electrons is also of the order of 100 Å.…”

“…[14,16] E po is much larger than (hγ 0 + 2.4 × 10 −20 J). Thus, from the excitation process of internal secondary electrons in semiconductors, [34] it is known that the energy of thermalized electrons obtained from primary electrons can also be greatrer than (hγ 0 + 2.4 × 10 −20 J). Therefore, from the assumption that f th in a NEASLP is independent of E obtainp when E obtainp > (hγ 0 + 2.4 × 10 −20 J) (i.e., thermalized electrons produced by photons at γ > [(hγ 0 + 2.4 × 10 −20 J)/h] have the same f th ) and that a NEASLP is also a NEASLD, [14,16] it can be stated that f th in a NEASLD is the same as that in a NEASLP produced by photons with hγ > (hγ 0 + 2.4 × 10 −20 J).…”