Low-energy photoelectron transmission through aerosol overlayers

TL;DR

This study investigates how low-energy photoelectrons pass through aerosol particle shells, revealing bi-exponential attenuation and providing insights into electron attenuation lengths in different aerosol materials.

Contribution

It presents the first analysis of low-energy photoelectron transmission through aerosol shells, comparing aerosol and thin film overlayer methods.

Findings

Bi-exponential attenuation of photoelectrons with shell thickness.

Attenuation length estimated at 8-9nm for thin shells.

Thicker shells show larger damping due to structural distortions.

Abstract

The transmission of low-energy (<1.8eV) photoelectrons through the shell of core-shell aerosol particles is studied for liquid squalane, squalene, and DEHS shells. The photoelectrons are exclusively formed in the core of the particles by two-photon ionization. The total photoelectron yield recorded as a function of shell thickness (1-80nm) shows a bi-exponential attenuation. For all substances, the damping parameter for shell thicknesses below 15nm lies between 8 and 9nm, and is tentatively assigned to the electron attenuation length at electron kinetic energies of ~0.5-1eV. The significantly larger damping parameters for thick shells (> 20nm) are presumably a consequence of distorted core-shell structures. A first comparison of aerosol and traditional thin film overlayer methods is provided.