Dopant enhanced neutralization of low-energy Li+scattered from Si(111)

Abstract

The neutralization of 3 keV Li + ions scattered from Si(111) is measured as a function of doping density, dopant type, and hydrogen coverage. When the surfaces are saturated with hydrogen to unpin the Fermi level, the neutral fractions decrease for lightly doped samples, but become anomalously large for highly doped n-type Si. A simple model that includes the manybody band-gap narrowing effect predicts the neutralization to good accuracy using a tunneling mechanism similar to the free-electron gas jellium model normally employed for ion/metal interactions, but excluding levels in the gap.

Nonadiabatic dynamics in energetic negative fluorine ions scattering from a Si(100) surface

“…The H − formation on a Si surface has been studied experimentally and theoretically. [31][32][33][34][35][36][37][38][39] The s character of the H − ion state is particularly simple because there is only one orientation of the atomic state with respect to the surface. In contrast, only a few studies on other types of negative ions have been performed so far.…”

“…25 As far as we know, there are only a few studies on semiconductor surfaces. [26][27][28][29][30][31][32][33][34][35][36][37][38][39] Most of these studies mainly involved the neutralization and negative-ion formation of positive projectiles scattering on silicon surfaces. The H − formation on a Si surface has been studied experimentally and theoretically.…”

Halogen Adsorption and Reaction with Bi2(Se,Te)3 and Bi/Bi2(Se,Te)3

“…47,56,57 For halogens adsorbed on bulk Bi 2 (Se,Te) 3 and Bi/ Bi 2 (Se,Te) 3 heterostructures, the electronegative halogen adatoms are expected to behave as hole donors, that is, as pdopants. p-Doping of an initially intrinsic semiconductor would normally increase the work function and consequently decrease the NF, 59 but the neutralization in alkali LEIS depends on the surface potential and not necessarily on the bulk doping because the surface Fermi level could be pinned by surface states. In Figure 3, the solid lines show the total yield TOF spectra and the shaded areas show the spectra of the scattered neutrals.…”